The invention relates to a solid powder multi-element composite infiltration agent and a composite infiltration process, and belongs to the technical field of metal surface treatment. The composite infiltration agent is composed of a chromium source, a vanadium source, a boron source, nickel powder, an activating agent, a filling agent, an oxygen scavenger and a rare-earth infiltration enhancer. The composite infiltration agent has the effects of rapid infiltration speed, no pollution, improving the structural density of an infiltration layer, and avoiding the embrittlement of the infiltrationlayer. The composite infiltration process comprises the following steps of carrying out acid pickling activation pretreatment on a base body material, then burying the base body material into the composite infiltration agent, heating and preserving heat in a carbon-containing or nitrogen-containing atmosphere, and then carrying out quenching treatment after furnace cooling. According to the process, the method is simple, no pollution occurs, the infiltration speed is rapid, the infiltration agent is free of hardening, and the surface of an infiltrated workpiece is clean. The prepared composite infiltration layer is fine in the crystalline grains and compact in the structure, has a good gradient structure, has the toughness, the wear resistance, the corrosion resistance, the high-temperature oxidation resistance and the like, and can be applied to parts such as a tool, a mold, a bearing, and a gear.