Now there are more and more new energy vehicles on the road, compare to the traditional vehicles that use the oil to offer the power, the new energy vehicles use electric or hydrogen to offer the power, which have no exhaust pollution emission, but also have non-exhaust emission. Brake and tyre system are the special components of vehicles due to the frequent replacement, they are the main source of the non-exhaust emission. Brake system is one of the most important safety systems of vehicles. The system can reduce the speed of the vehicle and keep the vehicle stable when going downhill. Friction between brake disc and pads or shoes during driving creates small particles that are released into the atmosphere, soil and rivers. The particles have different dimensions, some element or matter inside maybe harmful to human and environment. So it is very important to know more about the non-exhaust brake emission. Here, we focus on the specification of GRPE-81-12 “Non-Exhaust Brake Emissions – Laboratory testing – Part 1: Inertia Dynamometer Protocol to Measure and Characterise Brake Emissions Using the WLTP-Brake Cycle” and do the detailed interpretation.