The invention discloses a special engineering ship for immersed tube tunnel foundation sand filling. The special engineering ship for immersed tube tunnel foundation sand filling comprises a hull, anda monitoring system, a material mixing and conveying system and a sand pressing system are correspondingly arranged on the hull. According to the special engineering ship for immersed tube tunnel foundation sand filling, by arranging the monitoring system, the material mixing and conveying system and the sand pressing system, a difficult position of sand and ship separation and low efficiency inan immersed tube tunnel sand filling process in the past is changed, a sand filling effect monitoring system is additionally arranged, sand filling construction continuous proportioning is realized, pressure, flow and a water and sand ratio are effectively monitored, sand filling quality is ensured, and the sand filling work efficiency is improved by more than 50%.