The invention discloses a tri-axial exciting apparatus capable of off-
chip excitation of an MEMS
microstructure. The apparatus comprises a sleeve, a base plate, piezoelectric ceramics, a
pressure sensor, an upper connection block, a lower connection block, a
steel ball, elastic support members and the MEMS
microstructure, the upper end of the sleeve is provided with an annular top board, the
microstructure is arranged above the annular top board through the elastic support members, guide shafts are uniformly distributed between the top board and the base plate, the lower connection block is uniformly distributed with guide support arms penetrated by a sleeve wall and sleeving the guide shafts, the upper connection block and the lower connection block are respectively provided with a spherical groove and a tapered groove for clamping the
steel ball, extension springs are uniformly distributed between the upper connection block and the lower connection block in a circumferential manner,the piezoelectric ceramics are clamped between the
pressure sensor and the elastic support members, and the guide support arms are respectively provided with locking devices. According to the apparatus, different pre-tightening forces can be applied to the piezoelectric ceramics, obtained measuring values of the pre-tightening forces are more accurate, the adjusting process for compensating parallelism errors of two operating surfaces of the piezoelectric ceramics becomes more smooth, and the test of dynamic characteristic parameters is facilitated.