The invention provides a self-locking swinging hydraulic machine and belongs to the technical field of hydraulic machine structures. An ejector rod of the hydraulic machine is mounted in a casing in a sleeving manner and is in seal fit with the upper end of the casing, one end of a connecting rod is movably connected with one end, located in the casing, of the ejector rod, the other end of the connecting rod is movably connected with one end of a crankshaft, the other end of the crankshaft is fixedly connected with an output shaft of a swinging oil cylinder, the swinging oil cylinder, the crankshaft, the connecting rod and the ejector rod constitute a crank-link mechanism, and the swinging oil cylinder drives the ejector rod to reciprocate up and down; an upper limit bolt, a locking pin I, a lower limit bolt and a locking pin II are inserted after the crankshaft is located in place, so that the crankshaft is locked and fastened; sensing slots are formed in the positions, corresponding to a top dead center and a bottom dead center of the crank-link mechanism, of the output shaft of the swinging oil cylinder, and a sensor senses the positions of the sensing slots in the output shaft and sends an in-place signal outwards. The self-locking swinging hydraulic machine can realize stable self-locking in the top dead center and the bottom dead center of a travel and feeds back the in-place signal in time.