POLAR is a Compton polarimeter sensitive in the 50 to 500 keV energy range. The Crab pulsar is an import target for POLAR on board the Chinese space laboratory Tiangong-2 (TG-2). With its large Field of View (FoV), POLAR detected significant pulsed signals from the Crab pulsar which is visible by POLAR in about half of all observation time. In this work, we present the preliminary results including the pulse profile, timing and polarization measuring method. First, we show the highly significant pulse profile observed by POLAR which is compared to the results of other detectors including Fermi/LAT and INTEGRAL. The pulse profile as a function of theta incident angle and as a function of channel number, which shows that POLAR has a good detection performance, has also been showed. Second, we find that the timing of the Crab pulses is accurately measured, which provides a unique verification and calibration to the POLAR timing system. Finally, the potential polarization measurement of the Crab pulsar is discussed.