The invention provides a heat exchanger for a crude oil produced liquid. The heat exchanger comprises a casing, partition boards, a cooling liquid inlet, a cooling liquid outlet and a heat exchange pipe, wherein the partition boards comprise horizontal partition boards and vertical partition boards which divide a space in the casing into multiple relatively independent cooling spaces, and the multiple cooling spaces are communicated sequentially through communicating holes; the cooling liquid inlet is formed in the casing and is communicated with a cooling space at the upper stream of the multiple cooling spaces; the cooling liquid outlet is formed in the casing and communicated with a cooling space at the lower stream of the multiple cooling spaces; the heat exchange pipe is arranged in the casing, sequentially penetrates through the multiple cooling spaces and is provided with an oil inlet and an oil outlet, and the oil inlet and the oil outlet are arranged in two cooling spaces, relatively far away from each other, in the casing respectively. By means of the technical scheme, the problems of low heat exchange efficiency and high probability of blocking of heat exchangers in the prior art are effectively solved.