The reciprocating '一' shape scan method is presented to increase the scan efficiency of airborne laser detection equipment.Taken the agility of laser detection equipment in azimuth and pitch

and combined the valid scan process and fast reset process

searching and scanning the ground are realized

eliminating the effect of flight distance.The valid search route is like writing '一' back and forth.The projection of laser light spot on the ground is analyzed and the math model of this scan method is established.Four scan parameters of initial azimuth angle

ending azimuth angle

initial pitch angle and ending pitch angle in one cycle are given accoridng to flying parameter

scan angular speed and reset angular speed.Finally

the reciprocating '一' shape scan is validated and compared to 'Z' shape scan through simulation.The result shows that this method could improve scan efficiency from 5% to 10% than 'Z' shape scan does.