The invention discloses a variable-speed up-flow 
hydrolysis acidification reactor, which comprises a tank body. A central shaft is arranged at the center of the tank body, and the bottom of the central shaft is connected to a 
sewage inlet 
pipe and a tank 
bottom water distribution 
pipe. The top of the tank body is provided with a water 
distributor, the bottom of which is communicated with the central shaft. The water 
distributor is also connected with a 
reflux main 
pipe, the other end of which is connected to a multi-point water absorption 
reflux device located in the tank body. The 
reflux mainpipe is equipped with a flowmeter; a reflux pump is installed inside the reflux main pipe; water distribution ports are arranged on the tank 
bottom water distribution pipe; the 
tail end of each waterdistribution port is provided with a variable 
diameter plug; the top of the tank body is provided with an 
effluent catch basin; a 
sludge drain pipe is installed above the tank 
bottom water distribution pipe; and the 
sludge drain pipe is connected to a 
sludge pump outside the tank body. According to the invention, loss of 
activated sludge can be prevented, concentration of the 
effluent suspended substances is reduced, no mechanical stirring is needed, there is no 
power consumption, energy is saved and the environment is protected, water distribution is uniform, the water distribution pipelinesystem is prevented from being blocked, and the 
impact resistance is strong.