Trunk with extendible struture function

The utility model relates to a trunk with an extendible fixed structure. Both sides of a bag body are respectively provided with a slide type clamping device. The bag body is provided with a bag collecting part which is positioned in the middle section of the bag body. An upper bag part is arranged above the bag collecting part, and a lower bag part is arranged under the bag collecting part. An upper trunk body frame which is connected with the inner part of the upper bag part is fixedly connected with a slide block corresponding to a long groove. A lower trunk body frame which is connected with the inner part of the lower bag part is connected with a fixed plate. At least one long groove is arranged on the fixed plate, and the slide block which is extended out of the long groove is in lap joint and is buckled on a plate surface of the fixed plate by two outer margins. The bag body is pulled upward so that the slide block is driven to move up and down along the long grooves of the fixed plate and is positioned. The utility model has the advantages of firmness for trunk body and good bearing performance, and the volume of the trunk body is conveniently and easily adjusted.