Poly(N-methyl-5-vinyltetrazole)s (PMVT) was synthesized with poly(5-vinyltetrazole) (PVT) and dimethyl sulfate as primary materials with yield of up to 97.36%. The structure of PMVT was identified by IR and NMR. Further, the thermodynamic behavior of PMVT was studied by DSC-TG analysis, while the safety performance of PMVT was evaluated by the mechanical sensitivity testing. Results show that the temprature of thermal decomposition of the pendanted tetrazole group of PMVT is higher than that of PVT, and the sensitivity of PMVT is closed to that of PVT.