Suicidal thoughts and behaviors (STBs) are increasing among young people (aged 12-24 years) in China. Although Ecological Momentary Assessment (EMA) has been increasingly used to study STBs worldwide, no study has been conducted on young people with mood disorders (MD) in China. This mixed-method study aimed to evaluate the feasibility and acceptability of suicide risk monitoring in 75 young people with MD. Participants completed five to eight daily EMA surveys and wore smart bands for the EMA study. Semi-structured interviews were used to collect feedback. High adherence to EMA surveys (73.0 %) and smart bands (87.4 %) indicated feasibility. Participants reported an overall positive experience with the EMA study (helpful, friendly, and acceptable). Additionally, the reasons they were willing to comply with the EMA study were: (1) seeing the possibility of returning to "normal," and (2) experiencing the process of returning. However, a small proportion of participants had negative experiences (e.g., annoyance and missing prompts). The results of this mixed-methods study provide preliminary support for the feasibility and acceptability of using EMA (combined smartphones and wearable sensor devices) to assess suicidality among young people with MD in the Chinese cultural and social context.