The Instant Delivery Service (IDS) riders' overwork by “self-pressurisation” will not only reduce the level of their physical and mental health but also lose their lives in safety accidents caused by their fatigue riding. The purpose of this article is to examine whether there is overwork among IDS riders in big and medium cities in China? What's going on with them? Based on the Cobb-Douglas production function in the input-output theory, this study characterised the factors on IDS riders' safety and health associated with labour intensity. A mediating model with moderating effect was adopted to describe the mediation path for the 2,742 IDS riders who were surveyed. The results of moderating regression demonstrated that (1) 0.4655 is the total effect of labour intensity on the safety and health of IDS riders. (2) 0.3124 is the moderating effect that working hours make a greater impact on labour intensity. (3) The mediating effect of work pressure is the principal means of mediation both upstream and downstream.

Platform employers often have non-traditional labor relations, with labor flexibility and part-time work providing workers with a certain degree of freedom. However, the introduction of AI algorithms into these platforms has disrupted traditional workflows and altered work intensity, giving rise to the so-called "gig economy." This new economy has also brought with it a series of labor ethics issues, including the dispersion of employee rights, conflicts between labor and capital due to digital exploitation, shortened career paths, and mismatches between labor and contributions. This study employs structural equation modeling to investigate the impact of AI on labor ethics in flexible employment. Specifically, four variables are examined to assess the extent to which AI is being used to replace human labor. Labor ethics is evaluated through three dimensions, including labor alienation, labor relations, and job transfer. These dimensions are used to gauge changes in labor ethics. Ultimately, the study seeks to establish a structural equation model that sheds light on the labor ethics issues that arise as a result of the substitution of AI for human labor in flexible employment.