In order to grip miniature parts stably and safely by piezoelectric bimorph micro-grippers, a gripping force measurement method for piezoelectric bimorph micro-grippers based on equivalent elastic modulus is proposed. This paper establishes a gripping force calculating model according to the equivalent elastic modulus theory, proposes a measurement method in which the bimorph’s equivalent elastic modulus is tested in pre-experiments for the gripping force calculation, and conducts gripping force measurement experiments with a self-developed coarse-fine piezoelectric bimorph micro-gripper as an object. Experiment results indicate that the method has good measurement accuracy.