The invention discloses a dirty oil and 
sewage discharge device for a 
diesel engine bench experiment. The device comprises a dirty oil and 
sewage collection tank, a main conveying 
pipe, a conveying pump, an external 
pipe system and an 
electric control box, wherein the external 
pipe system comprises a plurality of collection pipes, an upstream part of the external pipe 
system is connected with a 
discharge hole of each 
test bench, a downstream part of the external pipe system is connected with the main conveying pipe, a downstream part of the main conveying pipe is connected to the dirty oil andsewage collection tank, the dirty oil and 
sewage collection tank is internally provided with a high 
liquid level sensor and a low 
liquid level sensor, a downstream part of the dirty oil and sewage collection tank is connected with a dirty oil 
treatment center through the conveying pump, the 
electric control box is connected with the conveying pump, the high 
liquid level sensor and the low liquidlevel sensor, and according to detection signals of the high liquid 
level sensor and the low liquid 
level sensor, start or stop of the conveying pump is controlled. The device is high in 
automation degree, saves materials, reduces the risk of 
contamination, avoids fire hazards, and has the advantages of reasonable structure, low cost, complete functions and simple operation.