A method for producing a counter-form (20) for manufacturing a part having a complex shape (24) by pressure sintering densification. The counter-form (20) is formed from successive layers produced by numerically-controlled three-dimensional (3D) additive printing according to the following steps: numerically recording a three-dimensional negative of the part to be produced (24) in a control unit of a three-dimensional additive printing system in order to constitute the positive form of the counter-form to be produced; producing the counter-form (20) using a 3D additive printing technique. The part having a complex shape (24d) is then manufactured by pressure sintering, then separated from the counter-form which is also sintered (20).