This 500 kW stationary power generation system uses an integrated technical route of on-line methanol steam reforming coupled with a PEM fuel cell. Aqueous methanol is used as feedstock to produce hydrogen on site and use it as generated. Methanol serves as a safe, efficient liquid hydrogen carrier, completely avoiding the safety risks and high cost of high-pressure hydrogen storage and transport. The equipment responds quickly and operates stably across all operating conditions, meeting needs for long-term continuous supply, grid-connected peak shaving, and off-grid independent supply. Multiple units can be paralleled and expanded to the megawatt class. Typical applications include industrial parks, zero-carbon parks, data centers, and integrated energy stations. The integrated modular design uses a standardized layout for convenient installation, commissioning, and later O&M.