The invention discloses a depth adaptive flexible acoustic transducer, comprising a submersible, wherein a groove is dug on the submersible; a cylinder body is mounted in the groove; a section of thecylinder body is a convex structure; a piston rod is mounted in the cylinder body through an O-shaped ring; the section of the piston rod is also the convex structure; a gas compression cavity is formed between a convex part at the bottom of the piston rod and an inner wall surface at the bottom of the cylinder body; a concave pit is set on a bottom surface at a position of a step of the inner wall surface of the cylinder body; the concave pit is communicated with the gas compression cavity; a gas inflation/deflation hole is set at one end of the bottom of the piston rod; a baffle ring is fixed at the very bottom of the cylinder body through a bolt; a communication hole is set in the middle of the piston rod; a watertight cable penetrates the middle of the communication hole; a watertightsocket is mounted at the bottom of the communication hole; and a piezoelectric ceramic module is mounted on the top of the communication hole. Through ingenious design of the cylinder body and the piston rod, the gas compression cavity is formed between a piston and the cylinder body, the movement of the piston is realized under an effect of internal and external pressure difference, and the transducing work of the submersible is realized conveniently.