The invention provides a crane lifting appliance positioning system and a positioning method. The positioning system comprises a trolley distance measuring sensor, a trolley distance measuring reflecting plate, a first crane distance measuring sensor, a first crane distance measuring reflecting plate, a second crane distance measuring sensor, a second crane distance measuring reflecting plate anda PLC control cabinet; and data measured by the trolley distance measuring sensor, the first crane distance measuring sensor and the second crane distance measuring sensor are transmitted to the PLC control cabinet and are calculated, so that the lifting appliance is accurately positioned. According to the positioning system and the positioning method, on the basis of a traditional positioning system, a set of crane distance measuring sensors and reflecting plates which are the same as the original design are added, so that the effect of eliminating the influence of the error caused by the gapbetween wheels and horizontal wheels and a track on the positioning precision is achieved.