The present invention relates to a moving block train operation control method and system based on train autonomous positioning, where the method is centered on a train-mounted device, autonomous positioning and integrity checking are implemented for the train-mounted device through satellites, and a movement authority and a target distance curve are calculated according to a real-time position, speed, and line state of a preceding train and in combination with train-to-train communication train safety protection technology, thereby achieving moving block. Compared with the prior art, the present invention has the advantages that line use efficiency, system work efficiency and operation efficiency are improved, a quantity of railside devices is reduced, and system construction and maintenance costs are reduced.