The invention relates to a technology and a device of lake water purification treatment, in particular to a technology and a device for treating and purifying the lake water using membrane integration process, which is characterized by comprising a pipeline type intelligent preprocess system, a porous membrane filtration device and a low pressure reverse osmosis device. The effluent quality and the stability are more excellent than the conventional water treatment because the post-processing is conducted to the lake water by adopting membrane integration technology. The device has advantages of small land occupation, large throughput of unit time and high automatization degree.