Using TVP-VAR model, this paper analyzed the impacts of import and export on economic growth in China. The results show that the influences of different technology industries’ import and export on the economic growth have obvious time-varying characteristics. The influences of low and secondary technology industries’ trades on China's economy are declining, and these industries' trades have formed inhibition effect on economic growth in recent years; however, the promoting effect of high technology industry's trade on economic growth is obviously enhanced. Therefore, under the background of new normal economy, although foreign trade can promote China's economic growth, it is necessary to optimize the trade structure for promoting the sustainable development of China's economy.