The special configuration of the bistatic forward-looking synthetic aperture radar(SAR) brings double square root and high squint angle to its range history, which makes it difficult to focus the echo signal, and puts forward higher requirements to the accuracy of the imaging algorithm. Therefore, a bistatic forward-looking SAR RD imaging method based on Chebyshev polynomials is proposed. Firstly, the geometry model and echo model are built, and the influence caused by separated configuration on determining stationary phase point during two-dimensional spectrum model deriving is indicated. Then, by the introduction of Chebyshev polynomials expansion replacing Taylor series expansion in the traditional imaging algorithm, the equivalent range model and the two-dimensional spectrum model of bistatic forward-looking SAR are derived. Finally, the phase matching functions of the bistatic forward-looking SAR RD imaging algorithm are determined by analysis, and the complete program of the imaging algorithm is given. The simulation results show that the proposed algorithm can significantly decrease the equivalent range error and spectrum expansion error of the bistatic forward-looking SAR, and improve the focus depth and imaging quality effectively