The invention, relating to the field of ceramic surface modification, discloses a power module metalized ceramic substrate and a metallization method thereof. The method disclosed herein comprises the following steps: firstly depositing copper or silver with a thickness of 0.1-5 mum on the surface of a power module ceramic substrate by magnetron sputtering or arc ion plating; then depositing copper, silver, copper alloy or silver alloy with a thickness of 50-1000 mum by chemical plating or electroplating; and finally depositing silver, gold, tin or nickel with a thickness of 0.1-5 mum by magnetron sputtering or arc ion plating, or depositing a tin or nickel layer with a thickness of 2-5mum by chemical plating or electroplating. According to the invention, the metalized ceramic component obtained by the method disclosed herein has large current-carrying capacity, strong thermal conductivity and heat dissipation capability, good gas tightness, reliable and stable quality, etc., is easily welded with other metals or ceramics and composite materials, and can be used in the fields of vacuum devices, aerospace, aviation, radio and television, communication, metallurgy, medicine, high-energy physics, etc.