The organic-inorganic piezoelectric material is a kind of molecular ferroelectric with the advantages of flexibility, flexible structure, easy film formation, solution phase synthesis, environmental protection and energy saving, etc., and can meet the needs of a new generation of thin film devices and wearable devices. In this paper, the organic-inorganic piezoelectric material TMCM-MnCl3 with perovskite molecular structure were prepared by the solution evaporation method with trimethyl halomethyl ammonium (TMXM, X=F, Cl, Br) as the organic part and MnCl2 as the inorganic part. The molecular structure, piezoelectric, thermal, acoustic and ferroelectric properties were characterized. The results show that the piezoelectric constant d33 is 106 pC/N, the Curie temperature is 130 ℃, and the acoustic impedance is about 16.5 MRayl, which is lower than that of the piezoelectric ceramics PZT-4(great than 33 MRayl), and it has broad application prospects.