Aiming at the problem that the erosion resistance of the cation sand stabilizer system for weakly consolidated sandstone reservoir is poor and the effective period of sand stabilization is short，a MS type molecular film stabilizer system combining good strength of resin binder with small permeability damage of quaternary ammonium salt was developed，and the molecular structure， molecular film erosion resistance，sand stabilization and fluid seepage performance of the stabilizer was evaluated. The results showed that the MS molecular film stabilizer system had higher strength and erosion resistance，the tensile strength was of 2.5 MPa，the elongation at break was up to 112%. The MS molecular film stabilizer system had higher ability of sand stabilization. When the mass fraction of MS stabilizer was 2%，the treatment amount was 2.0 PV，and the treatment time was 8 h，the sand production was less than 0.15 g/L. The MS molecular film stabilizer system had the function of blocking water and not blocking oil. When the mass fraction of MS stabilizer was 2%，the treatment amount was 2.0 PV，and the treatment time was 8 h ，the core water phase permeability reduced from 510×10-3 μm2 to 450×10-3 μm2，while the oil phase permeability basically unchanged，being of 782×10-3 μm2. The MS molecular film stabilizer achieved in-situ stabilization of the weakly consolidated formation particles by physical adsorption and chemical cementation to prevent sand production.