The invention relates to a method for controlling a direct-current motor by vector control, in particular to a predictive control method for current of a surface-mounted permanent magnet synchronous motor. The predictive control method comprises the following steps: I according to synchronous sampling and control cycle T sampling, sampling motor signals; II calculating the controlled voltage vector us (k+1) of the next moment, namely the (k+1) T moment; III carrying out current control; IV realizing predictive control for the current vector of SPMSM. The method combines the dynamic change nature of current and the current vector characteristic, improves the current control speed and precision, realizes accurate following of current vector, and overcomes the defect in the prior art that the current control speed is low and precision of the permanent magnet synchronous motor are low.