The invention discloses a time-frequency scale changing curve track bistatic foresight SAR imaging method, and mainly solves the problem that in the existing curve track bistatic foresight SAR imaging technology, parameter space-variant is serious, so that an image edge region cannot be focused at high resolution. According to the implementation scheme, the method comprises the following steps: acquiring a curve track bistatic forward-looking SAR echo signal, and performing range walking correction and second-order wedge-shaped time-frequency transformation on the echo signal; performing high-order migration correction and distance compression on the signals after time-frequency transformation, and completing distance direction processing of the echo signals; and constructing a high-order disturbance factor and a nonlinear scaling factor based on an azimuth space-variant model to reconstruct a signal azimuth frequency spectrum after range processing, obtaining echo signals with consistent Doppler parameters, and performing unified focusing on the echo signals to obtain a focused SAR image. According to the method, the edge region focusing depth of the curve track bistatic foresight SAR imaging image is improved, the image quality is improved, and the method can be used for foresight high-resolution detection.