A kind of epoxy mortar suitable for erosion-resistant and abrasion-resistant protection of high-head gate flow surface in sandy rivers was developed for the safe operation of hydraulic structures. According to the the working performance of the epoxy resin system, the primary formula was formed, then the orthogonal test was used to study the significance of the influence of different factors on the compressive strength and flexural strength of the epoxy mortar, so as to analyze the influence of cement-sand ratio and cement content on the mechanical properties of the mortar. Meanwhile, the internal pore size and distribution of epoxy mortar with different proportions were studied by nuclear magnetic resonance imaging technology, and the performance of different proportions of epoxy mortar against bed load abrasion was tested by a high-speed underwater steel ball grinder. The results show that the cement-sand ratio has a significant effect on the compressive strength and flexural strength of epoxy mortar. With the increase of the cement-sand ratio, the compressive strength and flexural strength of epoxy mortar first increase rapidly and then decrease to a certain extent. When the quartz sand∶cement∶epoxy resin is 5∶1∶3, the epoxy mortar is easy to mix and has good fluidity. After 7 days of curing, the internal pores of the mortar are evenly distributed, its compressive strength is 119.0 MPa, flexural strength is 42.24 MPa, and the thickness loss of 216 h high-speed underwater steel ball method is 0.063 mm. Combined with data analysis, high strength and high toughness epoxy mortar has high bonding strength, low construction difficulty and good abrasion resistance, which is suitable for gate flow surface protection.