A leading-edge structure for a passenger boarding bridge floor, the leading-edge structure being configured to be mounted on a front end edge of the passenger boarding bridge floor, wherein, the leading-edge structure of the passenger boarding bridge floor comprises: a protruding assembly that may be protruded or retracted relative to a passenger boarding bridge floor body, the leading-edge of the protruding assembly may abut against one side of a cabin door of an airplane; a protruding guide structure, which is arranged between the protruding assembly and the passenger boarding bridge floor body and configured to limit and guide protruding or retracting movement of the protruding assembly; and an energy storage assembly, configured to store energy during the protruding assembly retracts relative to the passenger boarding bridge floor body, and to release energy during the protruding assembly protrudes relative to the passenger boarding bridge floor body; wherein the protruding guide structure comprises a hinge assembly, the hinge assembly comprises a first member and a second member, each of which comprises a first end and a second end; the first end of the first member is hinged to the protruding assembly; the first end of the second member is hinged to the second end of the first member; the second end of the second member is hinged to the passenger boarding bridge floor; characterized in that the protruding guide structure further comprises a four-bar linkage structure; the four-bar linkage structure comprises a first bar, a second bar and a limiting bar, each of which comprises a first end and a second end, the first end of the first bar is hinged to the passenger boarding bridge floor, the second end of the first bar is hinged to the first end of the second bar, the second end of the second bar is hinged to the protruding assembly, the first end of the limiting bar is hinged to the second bar excluding end portions of the second bar, and the second end of the limiting bar is hinged to the passenger boarding bridge floor; in the extending direction of the protruding assembly, a second hinged point of the limiting bar is kept a first distance away from the first end hinged point of the first bar for a first distance L. a protruding assembly that may be protruded or retracted relative to a passenger boarding bridge floor body, the leading-edge of the protruding assembly may abut against one side of a cabin door of an airplane; a protruding guide structure, which is arranged between the protruding assembly and the passenger boarding bridge floor body and configured to limit and guide protruding or retracting movement of the protruding assembly; and an energy storage assembly, configured to store energy during the protruding assembly retracts relative to the passenger boarding bridge floor body, and to release energy during the protruding assembly protrudes relative to the passenger boarding bridge floor body; wherein the protruding guide structure comprises a hinge assembly, the hinge assembly comprises a first member and a second member, each of which comprises a first end and a second end; the first end of the first member is hinged to the protruding assembly; the first end of the second member is hinged to the second end of the first member; the second end of the second member is hinged to the passenger boarding bridge floor; characterized in that the protruding guide structure further comprises a four-bar linkage structure; the four-bar linkage structure comprises a first bar, a second bar and a limiting bar, each of which comprises a first end and a second end, the first end of the first bar is hinged to the passenger boarding bridge floor, the second end of the first bar is hinged to the first end of the second bar, the second end of the second bar is hinged to the protruding assembly, the first end of the limiting bar is hinged to the second bar excluding end portions of the second bar, and the second end of the limiting bar is hinged to the passenger boarding bridge floor; in the extending direction of the protruding assembly, a second hinged point of the limiting bar is kept a first distance away from the first end hinged point of the first bar for a first distance L.