Currently, the aging of population has become a common social problem. Emotion is an influential factor in the life quality for older people. Many studies have shown that affect labeling task can effectively improve the individual emotional experience. The present study proposes an online affect labeling task based on daily events and aims to improve the subjective life quality of older adults by promoting their emotional experience. A total of 232 older adults from Xi’an fill out the Subjective Well-being Scale. The participants whose life satisfaction and positive emotion scores were lower than the average and negative emotion score was higher than the average, were randomly assigned to the intervention group (n = 28) and the control group (n = 20). The intervention lasted two weeks. The intervention tasks included the emotional event reporting task and emotional labeling task. In the emotional event reporting task, the participants were asked to report an impressive daily life event which had a strong emotional response within 24 hours. In the affect labeling task, the participants needed to recall and re-experience the reported event and label their emotional experience using an emotional recording sheet. The intervention group had to complete the emotional event reporting task and the affect labeling task, while the control group only needed to complete the emotional event reporting task. After giving informed consent, the Subjective Well-being Scale and Emotional Ability Profile Scale were used to measure the older adults’ subjective well-being and emotional competence. We collected the older adults’ daily emotional experience by the experience sampling method. Using Mplus7.0 and R 3.3.3, the sampling data during 14 days were calculated to the emotional experience indexes, such as emotional stability and emotional complexity. We used SPSS 26.0 to compare the scores of the intervention group and control group in pre-test and post-test. To investigate the validity of the affect labeling task, covariance analysis was used to compare the scores of the intervention group and control group in post-test. The results showed that: (1) The identification of own emotions and understanding of own emotions for the intervention group were significantly higher than those for the control group; (2) The positive affect and subjective well-being for the intervention group were significantly higher than those for the control group, while negative affect for the intervention group was significantly lower than that for the control group; (3) In the daily emotional experience, the intensity of negative emotions for the intervention group was significantly lower than that for the control group, the mixed emotion for the intervention group was significantly lower than that for the control group, the mean square successive difference of negative emotion for the intervention group was significantly lower than that for the control group. These results indicated that the affect labeling task based on daily events can improve the identification of own emotions and the understanding of own emotions, can improve the older adults’ daily emotional experience effectively. Therefore, the affect labeling task can enhance older adults’ subjective life quality. In addition, the daily experience sampling method used in the present study can reduce participants' recall bias, improve the accuracy of the results, and the ecological validity of the research.