The invention discloses a sample fixing device and method for a bender element test. The device comprises a fixed rack and a press plate rack, wherein the fixed rack comprises a plurality of fixed support rods, the fixed support rod comprises a force transmission cylinder and a screw, a lower positioning rack is installed at the bottom of the fixed rack, an upper positioning rack and the press plate rack are installed at the top of the fixed rack in sequence from bottom to top, the lower positioning rack comprises a base installation tray and an installation rack A, a bender element base is installed in the base installation tray, the installation rack A is provided with a positioning groove A, the upper positioning rack comprises a top cap installation tray and an installation rack B, a bender element top cap is installed in the top cap installation tray, the installation rack B is provided with a positioning groove B, the press plate rack comprises a press tray and an installation rack C, and the top of the screw is connected with a positioning nut and an active nut through threads. Piezoelectric ceramic wafers of bender elements at an emitting end and a receiving end are guaranteed to be in the same plane, and the center connecting line of the bender elements is guaranteed to pass the center of a circle of the sample, so that accurate alignment is realized, and test accuracyand data reliability are improved.