A projection lens is disclosed. The projection lens includes, in sequence from an object side to an image side: an object surface, a first lens having positive refractive power, a second lens having negative refractive power, and a third lens having positive refractive power, where a focal length of the entire projection lens is f, a total optical length of the projection lens is TTL, a refractive index of the second lens is n2, a refractive index of the third lens is n3, and the following conditions are satisfied: 1.7≤n2≤2.2; 1.7≤n3≤2.2; and 1.25≤f/TTL≤2.20. The projection lens can effectively reduce the system length, and has good performance stability at different temperatures.