In order to study the contact bonding and fracture characteristics of particles during the dense forming process of mushroom residue,the uniaxial compression mechanical experiment and the detection of acoustic emission signals were carried out. Then, the simulation analysis was conducted by using the discrete element software PFC, and the contact bonding fracture of the mushroom residue particles, the characteristics of forcechain network, the stress-strain curves under different porosities, and the changes of particle structure were investigated. The results show that the acoustic emission counts increase with the increasing of stress, and at least 88.28% of the acoustic emission counts is contributed by tensile bonding fracture. When the strains are 0.2, 0.3, 0.4 and 0.5, the number of force chains increases to 6304, 7076, 8080 and 9258, respectively, and the continuous pressure enhances the bonding between particles. When the porosies are 0.36, 0.38 and 0.40, the number of contacts increases by 64.78%, 66.55% and 70.39%, respectively. The number of tensile fractures accounts for the total number of 85.67%, 90.20% and 88.28% respectively, which are much larger than the number of shear bonding fractures, and the particles are more inclined to fracture in the vertical direction of about 90°.