The invention relates to a particle scattering phase function measuring device and a measuring method. The invention aims to solve the problems in the conventional method that a big measuring error is caused by influences of surface reflection and inner interface multiple reflection of a glass container when a detector is arranged outside a transparent container and that a scattering phase function cannot be accurately obtained under the condition that the amount of suspended particle samples is small in the conventional measuring method. The measuring method comprises the following steps: 1, measuring scattering light intensity distribution of a standard particle system contained in a transparent circular cuvette under different scattering angles through an experiment; 2, obtaining a correction factor of a scattering phase function of the standard particle system under different scattering angles; and 3, measuring scattering light intensity distribution of a to-be-measured particle system through an experiment, correcting the scattering light intensity distribution of the to-be-measured particle system by utilizing the correction factor of the scattering phase function of the standard particle system, thereby obtaining the scattering phase function of the to-be-measured particle system. The measuring method disclosed by the invention is used for measuring the particle scattering phase function.