A　jet　cooling　system　is　designed　for　micro　Wankel　engines　in　laboratory　environment.　The　heat　transfer　on　the　wall　of　engine　is　simulated　with　FLUENT,　from　the　simulation　results　we　can　see　that　the　cooling　effect　of　jet　cooling　system　is　good,　it　can　meet　the　needs　of　wall　temperature.　This　paper　is　helpful　for　the　cooling　of　micro　engines　in　laboratory　environment.