Grid-forming (GFM) control becomes an emerging technology due to its advantages like frequency and inertial support, being a promising solution for the large-scale integration of renewable energy like solar photovoltaic (PV). In order to solve the fluctuation of the PV system (PVS) and reserve extra energy for frequency support, a battery energy storage system (BESS) is usually adopted. However, the PV-BESS needs collaborative control to manage the energy and support the grid flexibly. In this paper, a coordinated GFM strategy is developed for the PV-BESS to provide frequency support and achieve a better energy management. The coordinated PV-BESS GFM control allows the BESS to absorb power from the grid and participate in the regulation of the grid frequency. The coordinated PV-BESS GFM strategy has been validated by simulations in MATLAB and experimental tests on a lab-scale PV-BESS.