The development of new materials and the performance improvement of existing materials become an important subject from different aspects. In this paper, based on the theoretical research results of multiple piezoelectric effects, the influence of multiple piezoelectric effects on elastic coefficient of piezoelectric ceramics is studied. Theoretical analysis indicates that it is multiple piezoelectric effects that make piezoelectrics have two kinds of elastic and they result in the decrease of elastic compliance coefficients. Experimental validation is performed through PZT-5. Experimental results show that elastic compliance coefficient grows decreased by 0.912 times.