The invention belongs to the technical field of uranium mine exploration, and specifically relates to a method for defining a deep three-dimensional key advantageous metallogenic target area of a hydrothermal-type uranium deposit. The method comprises the following steps: 1, defining an equivalent uranium content abnormity range SA(eU); 2, defining a radon concentration abnormity range SA(Rn); 3,defining an advantageous uranium metallogenic area SF(U): defining an overlapped region of SA(eU) and SA(Rn) as the advantageous uranium metallogenic area SF(U); 4, defining a key advantageous uraniummetallogenic segment SI(U); 5, defining a three-dimensional key advantageous uranium metallogenic target area ST(U). The method employs the key physico-chemical prospecting method and the corresponding data processing technology, and is used for defining the deep three-dimensional key advantageous uranium metallogenic target area of the hydrothermal-type uranium deposit and locking the general spatial position of a deep uranium deposit.