Aiming at the problems such as excessive impact of bus voltage and unsynchronized phase of multiple PV inverters during the blackstart process in the solarstorage farm, the structure of solar-storage microgrid and micro-source control mode are studied. An improved V/f control strategy with variable d-axis bus voltage reference value is proposed to reduce the bus voltage impact during black start process. Based on the grid-forming virtual oscillator, the self-synchronization control topology of multiple parallel inverters with three-phase circuit are developed. An independent microgrid model is established. The tests of the bus boost, the PV inverter phase synchronization and the microgrid power balance are designed under different working conditions to verify the effectiveness of the control strategies. The results show that based on the designed control strategy and the structure, the bus voltage surge during the black start process can be reduced to within 2% of the rated voltage from original 5%. The unsynchronization degree of parallel inverters is also reduced. The maximum phase difference of multiple inverters is decreased to less than 1%; and the energy storage unit can quickly respond to photovoltaic power and load changes within 0.03 s. The black start process can be smoothly realized.