Abstract: The effects of laser space uniformity on shockwave planarity were studied by two methods. One is based on planarity of visible light generated from shockwave unloading at rear surface of target to judge planarity of shockwave; another is based on planarity of interference fringes jump discontinuity surface caused by the change of free surface velocity of target back to judge planarity of shockwave, which was measured by Imaging VISAR, and the hydrodynamic instability evolution could be known according to the lasting time of fringe moving. Research shows that the planarity of shockwave driven by the laser pulse of space heterogeneity of 2% is better, and the shockwave is capable of transmitting high speed flyer with good planarity and integrity; while the planarity of shockwave generated by the laser pulse of space heterogeneity of 5% becomes poor and complete high-speed flyer can not be transmitted. Results show that the laser uniformity has decisive effect on the shockwave planarity.