A testing method for X-ray detector is proposed through the study of the characteristics of pulsar radiation signals and the analysis of space observation requirements. Firstly, based on the photon radiation model, the probability formula of X-ray photon under detection is deduced, and the influences of different source flux and different detector time resolution on photon detection ability are analyzed. The relationship between pulse arrival time and the similarity of pulse profile is established by numerical simulations. And the observations of the crab pulsar of hard X-ray modulation telescope is processed, the pulse profile characteristics of the Crab pulsar at different energy are studied. Secondly, the testing and processing methods of X-ray detector for pulsar navigation are studied systematically, and the testing work of a self-developed focused X-ray detector is completed by using the ground testing system. The test results show that the background noise of the focused detector is 3.63×10^-5ph/(cm²·s^-1), the working energy range is 0.2~22.7 keV, the time resolution is 4.17 μs, and the spatial response is about 5'. The energy linearity of the detector is good, the integral nonlinearity is 0.52%. The energy resolution of the detector is better than 200 eV at five characteristic energy spectra, and the best detection efficiency is 39.18%@4.51 keV. Under the condition of weak pulse signal and strong background noise, the detector can accurately restore the pulse profile of Crab pulsar. The signal-to-noise ratio and similarity of the pulse profile increase with the increase of pulse flow and the decrease of background noise. The detector can detect the pulse signal whose radiation flux is 10 times less than the background noise in 2 400 s. The results show that the focused detector has excellent performance and can meet the space observation requirements of navigation pulsars(eg. PSR B1509), so the feasibility of the testing method is also verified.