The invention discloses a multifunctional water inlet connecting pipe for a diesel engine. The multifunctional water inlet connecting pipe for the diesel engine comprises a first branch flow channel,a second branch flow channel, a water inlet header pipe, an EGR cooler support and multiple water taking joints; one end of the first branch flow channel is provided with a first water outlet connecting port, and the other end is a first water inlet connecting port; one end of the second branch flow channel is provided with a second water outlet connecting port, and the other end is a second waterinlet connecting port; one end of the water inlet header pipe is connected with the first water inlet connecting port of the first branch flow channel and the second water inlet connecting port, andthe other end of the water inlet header pipe is a water inlet; the EGR cooler support is of a rectangular structure, is arranged at the top of one end of the first branch flow channel and the top of one end of the second branch flow channel and comprises multiple threaded hole lugs. According to the multifunctional water inlet connecting pipe for the diesel engine, through integrated design of theEGR cooler support function, supporting and fixing of an EGR cooler can be guaranteed while the cooling water flow of the engine is guaranteed effectively, the engine can meet China 6 emission requirements, and meanwhile, the performance and the reliability of the engine are improved.