To ensure that the laser proximity fuze can detect the ground target during the intersection between the laser detection system and the ground target, based on the dual-transmitter dual-receiver laser circumferential scanning detection mechanism, we established the constraint functions of scanning frequency and laser pulse frequency without missing measurement. According to the surface characteristics of the plane target, we derived the calculation models of the laser echo power and the minimum detectable echo power of the detection system to the plane target under the random intersection attitude. The calculation function of the angle between adjacent laser beams is obtained based on the minimum detectable echo power. We discussed the relation of the scanning frequency, the laser pulse frequency, the angle between adjacent laser beams and the intersection angle, focused on the influence of the intersection angle and the detection distance on the laser echo power. The simulation experiments were carried out under different laser peak powers and detection distances, the experimental results fully demonstrate that the laser echo power calculation model established in this paper is correct; the detection ability of the system is improved to a certain extent by increasing the laser peak power.