Three-dimensional force sensor used for abdominal cavity minimally invasive surgery instrument and use method of three-dimensional force sensor

The invention discloses a three-dimensional force sensor for an abdominal cavity minimally invasive surgical instrument and a use method of the three-dimensional force sensor. The three-dimensional force sensor comprises a strain elastomer and a fiber grating sensor, the strain elastic body is of an integrated structure and is made of an elastic material, the strain elastic body comprises an upper disc, a lower disc and three spiral beams, the top ends of the spiral beams are connected with the bottom end of the upper disc, the bottom ends of the spiral beams are connected with the top end of the lower disc, and the three spiral beams are distributed on the circumference of the upper disc and the circumference of the lower disc at intervals of 120 degrees; the fiber bragg grating sensor comprises a first fiber bragg grating, a second fiber bragg grating, a third fiber bragg grating and a fourth fiber bragg grating which are connected in sequence; the first fiber grating, the second fiber grating and the third