To reduce the run-off of fluid in sealing system, especially in the multiphase medium and extreme operating conditions, it is necessary to investigate the wetting and spreading behavior in silicon carbon (SiC) sealing face. Considering the sealing performance, ring-grooved structures with a varying depth ( h) and width ( w) are fabricated on SiC substrates by laser marking machine. The radius of structure’ inner surface is 1.5 mm, less than the capillary length of water. Then, experimental equipment is designed to observe the profile and the spreading behaviors of droplet on the surface, and the wetting performance and pinning effect are discussed, and the influences of depth and width of ring-grooves on the wetting performance can be obtained. The results show that the contact angle (CA) and the advancing contact angle (ACA) of smooth SiC surface are 70° and 76.5°, respectively. And the values decrease to CA 50° and ACA 54° after laser processing, which may be due to the average roughness (Ra) increasing from 0.1 μm in smooth surface to 0.8 μm in laser machined surface, making the hydrophilic surface more hydrophilic. The CA on the edge of ring-grooves increases to 138.5°, the control of fluid can be realized. When the droplet spreads along the radius direction before reaching the edge of groove, its CA keeps 76.5°. Once it reaches the edge, the position of contact line remains constant or changes slowly along the wall of groove(we are more inclined to the latter), and thus making the CA increase with the droplet volume increasing, until reaching a maximum apparent contact angle ( θ _max). And θ _maxin the experiment is less than that from the Gibbs equation, which is perhaps because of the mechanical vibration, the roughness of the wall or the liquid viscosity effect. After that, the droplet collapses, and spreads along the groove area, or even flows over the outer edge of the ring groove. The influences of hand wof groove are then studied, showing that θ _maxfirst increases linearly and then tends to be stable with the increase of h, and the depth of groove has a critical value ( h _c) of 80 μm. When h< h _c, the droplet moves along the wall to the bottom of groove, the droplet collapses after reaching the bottom under the surface tension function. However, when h≥ h _c, the droplet is in a stable condition, and collapses with the increase of volume. When h= 100 μm, a critical value of width ( w _c) of 40 μm exists for the geometrical relationships of ACA in wall between hand w. If wis too small, the droplet will contact the outer diameter of ring groove, which finally makes the droplet collapse and spread on the smooth surface. The present research can conduce to understanding the pinning effect in the solid edge and the spreading behavior of droplets in SiC surface.