The invention provides phosphate laser neodymium glass free of a thermo-optic effect. The phosphate laser neodymium glass free of the thermo-optic effect comprises the following components in molar percentage: 50-70mol% of P2O5, 3-25mol% of Al2O3, 5-25mol% of MO, 10-20mol% of R2O and 0.5-5mol% of R2O3, wherein the MO is one or more of BaO, MgO and ZnO; the R2O is one or more of Li2O, Na2O and K2O;the R2O3 is one or more of B2O3, Sb2O3 and Nd2O3. Through reasonable selection of the components and the contents thereof, a thermo-optic coefficient ds / dT is close to 0, the nonlinear refractive index n2 is reduced, the stimulated emission cross section of the neodymium glass is enlarged, and needs of a high-power laser device can be met.