The invention provides an ultrafiltration membrane treatment system and treatment process of heavy metal wastewater. The treatment process comprises the following steps: firstly carrying out water quality and quantity balance adjustment and pH adjustment of the heavy metal wastewater, adding chemical agents for coagulation, entering a tubular membrane component with a built-in tubular ultrafiltration membrane element for membrane filtration treatment, leading out filtrate, returning the concentrate to a concentrating tank, and then entering an ultrafiltration membrane treatment for circulating treatment to obtain final treatment effluent the water quality index of which is far lower than the national discharge standard. In the ultrafiltration membrane treatment system and treatment process of the heavy metal wastewater provided by the invention, by adopting the tubular ultrafiltration membrane component, the filtration flux is large, the efficiency is high, the cost is low, the membrane element has long service life, the membrane is convenient to clean, and the equipment occupation space is greatly reduced.