The invention discloses non-oriented electrical steel for an ultrahigh-effect constant-frequency compressor and a preparation method of the non-oriented electrical steel. The non-oriented electrical steel for the ultrahigh-effect constant-frequency compressor comprises the following chemical components of, in percentage by weight, 1.0%-1.90% of Si, 0.20%-0.9% of Als, 0.10%-0.60% of Mn, 0.01%-0.02% of P, less than or equal to 0.01% of C, less than or equal to 0.02% of S, less than or equal to 0.02% of N, less than or equal to 0.01% of Ti, less than or equal to 100 ppm of C+S+N+Ti, and the balance Fe and inevitable impurity elements. According to the reasonable component design, the technological technologies such as hot rolling, normalizing, cold rolling, continuous annealing and the like are matched to optimize, so that the non-oriented electrical steel for the ultrahigh-effect constant-frequency compressor is obtained, which the thickness of 0.5mm, P1.0/50 is less than or equal to 3.20W/kg, B5000 is greater than or equal to 1.72T, the yield strength Rp0.2 is less than or equal to 350 MPa, and the transverse longitudinal strength difference delta Rp0.2 is less than or equal to 10 MPa.