Three typical linear current control strategies for grid-connected inverters are compared. Firstly， the structure and characteristics of linear current control strategies with three different reference frames are introduced. Then with spectrum shift theory， the essential of dq synchronous reference frame control is revealed， and its equivalent structure under αβ stationary reference frame is derived. Besides， concern on the steady-state errors， dynamic response and grid disturbance rejection， the performance of three different linear current control strategies are compared theoretically. Finally， the simulation results with MATLAB are presented. Theoretical analysis and simulation prove that the performance of dq synchronous reference frame control and αβ stationary reference frame control are much better than abc natural reference frame control， whereas the dynamic performance of the three are similar.