The invention discloses a storage safety distance monitoring method, device and system. The method includes the steps of determining all surfaces to be monitored on the basis of multiple pile locations divided in advance in a warehouse; in a condition that the warehouse is not occupied, obtaining a first distance between an obstacle and a range finding device for each surface to be monitored when the range finding device is scanning all angles; in a condition that the warehouse stores objects on the basis of pile locations, obtaining a second distance between the obstacle and the range finding device for each surface to be monitored when the range finding device is scanning all angles; determining whether the first distance and the second distance are equal at all angles; and determining whether an alarm triggering condition is satisfied if the first distance and the second distance are not equal, and triggering the alarm if the alarm triggering condition is satisfied. Through the above technical scheme, a plane divided by three dimensional grids is scanned and calculated in real time, and then safety monitoring of five distances can be achieved.