Detection method of laser radar and laser radar

The invention provides a detection method of a laser radar and the laser radar, and relates to the technical field of laser radars, and the method comprises the steps: generating at least two beams of first and second combined wave detection signals and at least two beams of first and second local oscillator signals; receiving a first local oscillator signal, a second local oscillator signal and a first combined echo signal; and receiving the first local oscillator signal, a second delay local oscillator signal obtained by delaying the second local oscillator signal, and a second combined echo signal, and determining the speed of the target object relative to the laser radar according to the extremum frequencies in the first and second beat frequency signals, the extremum frequencies in the third and fourth beat frequency signals, and the sweep frequency direction. The first to second beat frequency signals are obtained through beat frequency of the first local oscillator signal, the second local oscillator s