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.