Photovoltaic（PV） generation is still considered to be an energy-replacement rather than capacity-replacement source and absent from power balance because of its fluctuating and intermittent nature. PV output is proven to have strong relationship with load and plays peak-shaving role in most cases， as such ignoring its capacity value will lead to serious waste of resources. As the PV penetration increases rapidly in recent years， evaluation of PV capacity credit is becoming one of the hottest issues in power system planning. Firstly， the evaluation metrics and methods of PV capacity credit are summarized. Evaluation metrics are classified by their characteristics and a recommended metric is given according to the results of comparison; evaluation methods are discussed in detail， including the research hotspots and developing directions. Secondly， improvement measures of PV capacity credit are proposed from aspects of PV power station， grid side and demand side. Furthermore， the feasibility，prospects and related technology are analyzed. Finally， the safeguard measures of PV capacity credit from the point of power system flexibility are explored.