To demonstrate repetitive-intense X-ray source by using pulsed-power discharge, we proposed an innovative X-pinch method using compact pulse generator and liquid metal injection. The compact pulse generator using small pulse-forming-network modules (PFNMs) has been developed. The current rising rate of the PFNMs with X-pinch system is over 0.1 kA/ns at low operation voltage. To suppress the expansion of liquid metal in a vacuum chamber, we have demonstrated liquid metal injection with coaxial supersonic flow generated by an aerospike nozzle. The results indicate that the expansion of liquid metal is suppressed with the coaxial supersonic flow.