Abstract: According to the data of CGSS in 2017 and 2018, the influence of the social network on the physical and mental health of the urban and rural elderly was explored by using orderly Logistic regression combined with the KHB test of mediating effect. The results showed that Internet use, relatives and friends had a significant impact on improving the physical and mental health of the elderly.Among them, relatives had a heterogeneous impact on the health of urban and rural elderly, and there were significant urban-rural differences in Internet use. The mediating effect of leisure participation was significant. Therefore,the government should optimize community culture, entertainment, education, physical exercise and other elderly care service facilities, focus on accelerating the development of rural cultural undertakings, and promote the construction of rural civilization, at the same time, improve the construction of rural information network facilities, narrow the difference in Internet penetration rates between urban and rural areas, conduct targeted Internet application skills training,strengthen Internet security supervision for the elderly,and create a safe Internet environment for the elderly.

Key words: social network, urban and rural elderly, physical and mental health, leisure participation, mediating effect