An in situ deposition method of an abradable coating by additive manufacturing on a turbomachine casing, consisting of depositing on an internal surface of said turbomachine casing (20A, 62) a filament (100, 200, 300, 400, 500, 600) of an abradable material in a predefined deposition path in order to create a three-dimensional scaffold of filaments forming between them an ordered array of channels, the method comprising the following steps: positioning a filamentary material deposition system along a longitudinal axis of said casing at a predetermined position and distance relative to said internal surface of said casing, depositing a first layer of said abradable coating on 360° of the circumference of said casing by a relative circumferential displacement between said casing and said filamentary material deposition system, carrying out a rotation of said filamentary material deposition system by a first predetermined angle and positioning said filamentary material deposition system along said longitudinal axis of said casing at a predetermined position and distance relative to said first layer of said abradable coating, depositing, on a sector of said casing by a relative axial displacement between said casing and said filamentary material deposition system, a second layer of said abradable coating on said first layer of said abradable coating, carrying out a relative circumferential displacement between said casing and said filamentary material deposition system by a predetermined angular deviation corresponding to the first sector already covered during the deposition of said second abradable coating layer, and repeating the step of depositing on said casing sector and the step of relative circumferential displacement by said predetermined angular deviation for the following sectors until 360° of the circumference of said casing are covered, and after having carried out a rotation of said filamentary material deposition system by a second predetermined angle, repeating all the preceding steps for the following layers until a desired abradable coating thickness is obtained. positioning a filamentary material deposition system along a longitudinal axis of said casing at a predetermined position and distance relative to said internal surface of said casing, depositing a first layer of said abradable coating on 360° of the circumference of said casing by a relative circumferential displacement between said casing and said filamentary material deposition system, carrying out a rotation of said filamentary material deposition system by a first predetermined angle and positioning said filamentary material deposition system along said longitudinal axis of said casing at a predetermined position and distance relative to said first layer of said abradable coating, depositing, on a sector of said casing by a relative axial displacement between said casing and said filamentary material deposition system, a second layer of said abradable coating on said first layer of said abradable coating, carrying out a relative circumferential displacement between said casing and said filamentary material deposition system by a predetermined angular deviation corresponding to the first sector already covered during the deposition of said second abradable coating layer, and repeating the step of depositing on said casing sector and the step of relative circumferential displacement by said predetermined angular deviation for the following sectors until 360° of the circumference of said casing are covered, and after having carried out a rotation of said filamentary material deposition system by a second predetermined angle, repeating all the preceding steps for the following layers until a desired abradable coating thickness is obtained.