The stability of linear frequency modulated signals generated by optical fiber structure is easily affected by experimental devices and environmental factors, which leads to the change of amplitude and phase characteristics of the generated signal, and then affects the detection performance of photonic time-stretched coherent radar system. This paper mainly analyzes the impacts of experimental devices and environmental factors on detection performance of linear frequency modulated signals, including splitting ratio of optical couplers, center wavelength shift of the filter and delay perturbation of the interference arm. By simulating peak power and range resolution of signals after pulse compression under different conditions, comparing them with the results after pulse compression under the ideal condition, the influence of every factor and the parameter range to ensure the detection performance are obtained, which can provides a reference for design and implementation of photonic time-stretched coherent radar.