Abstract: In order to solve the problems of small measurement range of field of view, high precision and difficult measurement in a portable laser communication, link energy at a specified communication distance was used as the basis for measuring the field of view. A measurement method of field of view based on portable laser communication was proposed. A high-precision measurement device was designed and the actual test and measurement were carried out. The results show that, when detector sensitivity is -30dBm, the receiving field of view of laser communication at 1km, 2km, 3km, 4km is 1.12mrad, 0.94mrad, 0.87mrad and 0.63mrad respectively. The test method and device can accurately measure the field of view of a portable laser communication. The test device can be extended to high-precision measurement of small field of view in different fields.