Abstract: Taking the chock shield supports as the object of study, methods for measuring and calculating the external load of powered supports were discussed. Selecting the angle parameters as variables, the simple formulae of interactive computation with respect to the work angles of a powered support were deduced and verified by an example. Furthermore, the formulae determining the magnitude, direction and action point of the external load were put forward. The investigation results have provided a sound basis for the software design of the intelligent instrument for load measuring of powered supports.