A catheter positioning device for positioning a catheter on a body, comprising: a base fixedly arranged on the body; a positioning guide groove arranged on the base and configured for accommodating the catheter; and a plurality of self-locking modules (13, 130a-130c) arranged on the base and positioned on two opposite sides of the positioning guide groove, characterized in that each self-locking module (13, 130a-130c) comprises: a V-groove; and a self-locking unit movably arranged in the V-groove, wherein a first terminal of the self-locking unit is provided with a contact portion which is configured to be in contact with an outer pipe wall of the catheter arranged in the positioning guide groove, and the self-locking unit moves in the V-groove to switch between a released state and a locking state; wherein, when the catheter is positioned at a preset position in the positioning guide groove, each self-locking module (13, 130a-130c) is in the released state; when the catheter moves relative to the positioning guide groove to deviate from the preset position, the self-locking unit is interlocked in the V-groove by the contact portion and the outer pipe wall of the catheter, and the self-locking unit is automatically switched from the released state to the locking state, so that the movement of the catheter relative to the positioning guide groove is limited by mutual coordination of the self-locking modules (13, 130a-130c) which are arranged on the two opposite sides of the positioning guide groove and are in locking state. a base fixedly arranged on the body; a positioning guide groove arranged on the base and configured for accommodating the catheter; and a plurality of self-locking modules (13, 130a-130c) arranged on the base and positioned on two opposite sides of the positioning guide groove, characterized in that each self-locking module (13, 130a-130c) comprises: a V-groove; and a self-locking unit movably arranged in the V-groove, wherein a first terminal of the self-locking unit is provided with a contact portion which is configured to be in contact with an outer pipe wall of the catheter arranged in the positioning guide groove, and the self-locking unit moves in the V-groove to switch between a released state and a locking state; wherein, when the catheter is positioned at a preset position in the positioning guide groove, each self-locking module (13, 130a-130c) is in the released state; when the catheter moves relative to the positioning guide groove to deviate from the preset position, the self-locking unit is interlocked in the V-groove by the contact portion and the outer pipe wall of the catheter, and the self-locking unit is automatically switched from the released state to the locking state, so that the movement of the catheter relative to the positioning guide groove is limited by mutual coordination of the self-locking modules (13, 130a-130c) which are arranged on the two opposite sides of the positioning guide groove and are in locking state. a V-groove; and a self-locking unit movably arranged in the V-groove, wherein a first terminal of the self-locking unit is provided with a contact portion which is configured to be in contact with an outer pipe wall of the catheter arranged in the positioning guide groove, and the self-locking unit moves in the V-groove to switch between a released state and a locking state; wherein, when the catheter is positioned at a preset position in the positioning guide groove, each self-locking module (13, 130a-130c) is in the released state; when the catheter moves relative to the positioning guide groove to deviate from the preset position, the self-locking unit is interlocked in the V-groove by the contact portion and the outer pipe wall of the catheter, and the self-locking unit is automatically switched from the released state to the locking state, so that the movement of the catheter relative to the positioning guide groove is limited by mutual coordination of the self-locking modules (13, 130a-130c) which are arranged on the two opposite sides of the positioning guide groove and are in locking state.