A frequency conversion control method, apparatus and system for a linear electric motor. The method comprises: determining a set frequency and a set position at various moments in a stroke of a mover of a linear electric motor; at each moment in the stroke, calculating a first frequency deviation according to a feedback position of the mover of the linear electric motor at a current moment and a current set position of the mover of the linear electric motor, acquiring a second frequency deviation at an oscillation inhibition stage, and correcting a set frequency at the current moment according to the first frequency deviation and the second frequency deviation so as to obtain a final given frequency at the current moment; calculating a target output voltage of a frequency converter at the current moment by means of the final given frequency at the current moment and a pre-set V/F control curve within a current time period; controlling the running of the linear electric motor according to the final given frequency at the current moment and the target output voltage of the frequency converter; and when a running frequency of the linear electric motor reaches a reversing frequency point, performing direct current braking within a pre-set time. The present solution can favourably realize the stable and reliable running of a linear electric motor.