The invention discloses a grapefruit-peel-like structure capsule for wrapping STF and a preparation method thereof. The method comprises the following steps of: dripping STF into liquid paraffin and aW/O emulsifier, and uniformly stirring and mixing to obtain a W/O emulsion; dripping the W/O emulsion into sodium alginate and an O/W emulsifier, stirring and mixing uniformly to obtain W/O/W emulsion; dropping the W/O/W emulsion into aqueous solution containing calcium ions at a uniform speed to form spherical gel beads; carrying out post-treatment on the gel beads to obtain the grapefruit-peel-like structure capsule for wrapping the STF. The capsule comprises solid calcium alginate and W/O emulsion; the solid calcium alginate forms a surface compact layer and an inner porous structure; theinternal porous structure is filled with the W/O emulsion. The preparation method is simple, low in cost and easy to achieve. Due to the toughness of the dense layer of the surface layer, the buffering action of the internal porous structure and the action of the SFT, the capsule has better buffering performance when subjected to impact.