The utility model belongs to the technical field of nickel electrolysis diaphragms. The utility model discloses a nickel electrolysis diaphragm bag. In order to solve the problems in a nickel electrolysis diaphragm bag in the prior art, the nickel electrolysis diaphragm bag comprises a bag body formed by sewing front diaphragm cloth, rear diaphragm cloth, two pieces of side diaphragm cloth and bottom diaphragm cloth, attaching linings are pasted to the sewing positions, a first diaphragm cavity is formed in the upper end of the front diaphragm cloth, and a second diaphragm cavity is formed inthe upper end of the rear diaphragm cloth. According to the utility model, the original common flat diaphragm bag structure is redesigned into a cuboid structure, so that workers can conveniently penetrate through the cathode plate, the working efficiency is greatly improved, the condition that the diaphragm bag is broken down by the cathode and the anode which are electrically connected is reduced, the loss of the diaphragm bag is reduced, and the production cost is saved on the aspect of overall production. According to the utility model, a worker can conveniently penetrate through the cathode plate, the working efficiency is greatly improved, the condition that the cathode and the anode are electrically connected to puncture the diaphragm bag is reduced, the loss of the diaphragm bag isreduced, and the production cost is saved on the whole production.