This article uses the "Chinese Family,Nutrition and Health Survey" (CHNS)data, measure the effect of maternal labor force participation on child health in rural China,focusing on calculate the effect of full-time labor participation,part-time labor participation,and at different age stages of participation.The results show that:maternal labor force participation does not necessarily resuh in reduced time of mother care,mothers who at part-time working have more flexibility time even take care of their children more fully.On the other hand,maternal labor force participation can increase the income of family,SO have positive effect on child health,but the effect of part-time work is not significant.Control the reaction of child health on mother labor supply,mothers enter the labor market at children's 0~2 years old have negative effect on child health,and the degree of impact between 0.490-0.638.