The invention relates to a duct-piece spigot-and-socket connection structure. Weakening of the connection structure to a duct piece structure is reduced to the greatest degree, the convenience and timeliness of duct piece installation are greatly improved, and the risk is effectively avoided that a connection component falls down in the tunnel operation period. A hand hole and a spigot-and-sockethole which are connected through a straight hole channel are formed in a preorder duct piece, and a mounting hole corresponding to the spigot-and-socket hole is formed in a postorder duct piece. An assembly component comprises an embedded thread sleeve, a straight screw, a long nut and a spacer, the embedded thread sleeve is fixedly embedded in the mounting hole, the front end of the straight screw is in threaded connection with the embedded thread sleeve, a main body of the straight screw penetrates through the mounting hole and enters the spigot-and-socket hole, the rear end of the straightscrew is in threaded connection with the long nut which penetrates through the straight hole channel through the hand hole and enters the spigot-and-socket hole, and the rear end of the long nut is applied to the hole wall of the hand hole through the spacer. Guide sleeves embedded in the long screw are arranged in the mounting hole and the spigot-and-socket hole, the peripheries of the guide sleeves are in contact with the hole walls of the mounting hole and the spigot-and-socket hole, and the guide sleeves have the guide and positioning functions on splicing of the preorder duct piece and the postorder duct piece.