A method for implementing a sliding spotlight Synthetic Aperture Radar, SAR, comprising: calculating a maximal scanning angle and an antenna size of a sliding spotlight SAR based on system parameters of the sliding spotlight SAR; determining a number of antenna sub-arrays of the sliding spotlight SAR meeting a first condition defining a distance between the antenna sub-arrays; determining a Pulse Repetition Frequency, PRF, meeting a second condition and a third condition, wherein the second condition is for defining that no pulse transmitted by the sliding spotlight SAR falls into an echo window, and the third condition is for defining that no nadir-echo interference to the sliding spotlight SAR falls into the echo window; acquiring information on a beam position of the sliding spotlight SAR based on the PRF meeting the second condition and the third condition; calculating a key parameter of the sliding spotlight SAR based on the beam position of the sliding spotlight SAR, wherein the key parameter comprises information on at least one of an azimuth ambiguity-to-signal ratio, a range ambiguity-to-signal ratio and a noise equivalent sigma zero; and determining that the number of antenna sub-arrays of the sliding spotlight SAR meets the first condition and that the PRF of the sliding spotlight SAR meets the second condition and the third condition when it is determined that the key parameter of the sliding spotlight SAR meets a preset index, wherein the step of determining a PRF meeting a second condition and a third condition comprises: determining the PRF meeting the second condition according to formula: i 2 ⁢ R n / c - T p - T p ⁢ t ≤ P ⁢ R ⁢ F ≤ i + 1 2 ⁢ R f / c + T p + T p ⁢ t, and determining the PRF meeting the third condition according to formula: j 2 ⁢ R n / c - T p - T p ⁢ t - 2 ⁢ H / c ≤ P ⁢ R ⁢ F ≤ j + 1 2 ⁢ R f / c + T p + T p ⁢ t - 2 ⁢ H / c wherein T p is a width of the pulse transmitted, T pt is a protecting time, R n and R f are a near-end slant range and a far-end slant range, respectively, c is the speed of light, i and j are a positive integer, respectively, and H is the actual height of a satellite. calculating a maximal scanning angle and an antenna size of a sliding spotlight SAR based on system parameters of the sliding spotlight SAR; determining a number of antenna sub-arrays of the sliding spotlight SAR meeting a first condition defining a distance between the antenna sub-arrays; determining a Pulse Repetition Frequency, PRF, meeting a second condition and a third condition, wherein the second condition is for defining that no pulse transmitted by the sliding spotlight SAR falls into an echo window, and the third condition is for defining that no nadir-echo interference to the sliding spotlight SAR falls into the echo window; acquiring information on a beam position of the sliding spotlight SAR based on the PRF meeting the second condition and the third condition; calculating a key parameter of the sliding spotlight SAR based on the beam position of the sliding spotlight SAR, wherein the key parameter comprises information on at least one of an azimuth ambiguity-to-signal ratio, a range ambiguity-to-signal ratio and a noise equivalent sigma zero; and determining that the number of antenna sub-arrays of the sliding spotlight SAR meets the first condition and that the PRF of the sliding spotlight SAR meets the second condition and the third condition when it is determined that the key parameter of the sliding spotlight SAR meets a preset index, wherein the step of determining a PRF meeting a second condition and a third condition comprises: determining the PRF meeting the second condition according to formula: i 2 ⁢ R n / c - T p - T p ⁢ t ≤ P ⁢ R ⁢ F ≤ i + 1 2 ⁢ R f / c + T p + T p ⁢ t, and determining the PRF meeting the third condition according to formula: j 2 ⁢ R n / c - T p - T p ⁢ t - 2 ⁢ H / c ≤ P ⁢ R ⁢ F ≤ j + 1 2 ⁢ R f / c + T p + T p ⁢ t - 2 ⁢ H / c determining the PRF meeting the second condition according to formula: i 2 ⁢ R n / c - T p - T p ⁢ t ≤ P ⁢ R ⁢ F ≤ i + 1 2 ⁢ R f / c + T p + T p ⁢ t, and determining the PRF meeting the third condition according to formula: j 2 ⁢ R n / c - T p - T p ⁢ t - 2 ⁢ H / c ≤ P ⁢ R ⁢ F ≤ j + 1 2 ⁢ R f / c + T p + T p ⁢ t - 2 ⁢ H / c wherein T p is a width of the pulse transmitted, T pt is a protecting time, R n and R f are a near-end slant range and a far-end slant range, respectively, c is the speed of light, i and j are a positive integer, respectively, and H is the actual height of a satellite.