Turnable plate rail transfer cart is a kind of transfer cart which can run on the 90 degree turning railway. Working principle: when the transfer cart runs on the turnplate, turn the turnplate automatically or with manpower to connect the railway on the turnplate with the 90 degree turning railway, and then the transfer cart will run on the 90 degree turning railway. This turnplate rail transfer cart is suitable to be used on the annular railway and crossing railway for the equipment's producing line. The turnplate system has the features of stable driving, high accuracy of rail connection and can be totally automatically operated.