Abstract: As a novel single photon detector, the superconducting nanowire single photon detector can work in constant current mode with high sensitivities, low dark counts, and high detecting efficiencies for 1064 nm wavelength laser. Applying the detector to satellites with retroreflectors and space debris without any retroreflector laser ranging experiments in nighttime, a set of good observing data was obtained. To make advantages of this detector in space target laser ranging, the feasibility of employing it to daylight laser ranging system was studied and analyzed through the daytime laser ranging experiment and the actual response output measurement for daytime sky background light. The navigation satellite glonass134 (~20 000 km) and the low-orbit satellite hy2a were measured before sunset; the maximum counts output of the single-photon superconducting detector could reach up to 2 MHz during the actual daytime sky background light measurement. The results show that using the superconducting single photon detector as echo detector can realize a high performance and high efficiency daytime laser ranging system.