The utility model provides an automatic monitoring device of railway vehicle loading safety. The automatic monitoring device of the railway vehicle loading safety is installed between an upper sleeper beam and a lower sleeper beam of vehicle. The automatic monitoring device of the railway vehicle loading safety includes a switch-type magnet base installed on the lower end of the lower sleeper beam in a magnetically absorbing manner; a telescopic push rod arranged in a shell, having an upper part exposed outside the shell and an upper end abutting against the inner side of the upper sleeper beam and being capable of extending and retracting freely through a return spring; the return spring arranged between the bottom end and the shell; a measurement module sleeved on the telescopic push rod and including a zero-setting press button arranged on the shell, and a displacement sensor , a data processing unit and a wireless transmitter arranged in the shell; and a handheld microcomputer. The displacement sensor collects displacement data of the upper sleeper beam and the displacement data is transmitted to the handheld microcomputer through the wireless transmitter after being processed by the data processing unit. By using the automatic monitoring device of the railway vehicle loading safety provided by the utility model, changes of loading weight in a loading process can be monitored in real time, and phenomenon of overloading and unbalance loading can be found timely. And the automatic monitoring device of the railway vehicle loading safety is simple in structure, low in weight, small in size and easy in installation, and has very high practical value.