The selection of suitable raw materials is an important method to improve the performance of magnesium phosphate cement. By changing the kind and amount of polymer emulsions added in magnesium phosphate cement, the applicability of polymers was studied. The results show that the viscosity of polymer emulsions is well correlated with the density, fluidity and setting time of modified magnesium phosphate cement; the pH value of polymer emulsions is an important factor affecting the mechanical properties of modified magnesium phosphate cement; the effect of a suitable polymer emulsion and its dosage on the compressive strength of modified magnesium phosphate cement is comparatively less, but it can improve the bond strength and flexural strength of the material and significantly increase its fracture energy. Adding polymer emulsions does not change the type of hydration products. However, the morphology of hydrated products and its dense degree are significantly affected.