In this paper, we studied the geometries, stabilities, band structures and densities of states of copper, silver and gold doped phosphonenes. The biggest distortion of geometric structure is the structure of gold doped phosphonene, however, it is the most stable structure among three doped systems. The band structure of phosphonene can be tuned by doping copper, silver and gold metal atoms. Meanwhile, there are two impurity levels in the doped phosphonene systems, one donor level and one acceptor level, respectively. The enhancement of the conductivity of phosphonene is undeniable due to the introduction of impurity levels.