For the first time, a facile and low-cost method for fabrication of ultrasensitive microelectrode arrays (MEA) lead ions sensor based on heat-shrinkable polymer and modified with graphene-bismuth nanocomposites was presented. The characterization result indicated that the electrode surface presented unique wrinkle structure by heating-shrink process. Due to the non-linear diffusion characteristic of the micro electrode, the unique micro-wrinkle structure, and excellent catalytic activity of Bi NPs, performance of the sensor had been improved greatly. The lead ions stripping peak current (Faraday current) and sensitivity increased notably, and the sensor's detection limit was achieved as 0.016 ppb. This is a very simple and low-cost but effective way to detect ultra-low concentrations lead ions and the microelectrode arrays based on heat-shrinkable film can be applied to many fields.