GaN-based optoelectronic devices have been an important development direction for semiconductors and have been applied in several fields. P-type GaN thin film implementation is the core process for optoelectronic devices, and a lot of breakthrough results have been achieved in p-GaN research. For example, Si and Mg are used as the main doping elements. However, more effective doping of GaN materials is needed in order to make GaN materials play a greater electrical and optical advantage. In this paper, we take p-GaN as the main object of study and outline the conditions that need to be satisfied for effective doping of GaN materials. Emphasizing several factors that make the quality of p-type materials of GaN a bottleneck for application development, the results achieved in p-GaN research in recent years are presented.