Powdery rust of bronze ware—a “bronze disease”—is harmful. Since it seriously corrodes the matrix of bronze and is difficult to cure, and its malignant expansion can make an intact bronze completely crisp in a short time, it is also called a “bronze cancer”. With more than a century of in-depth research on the powdery rust of bronze, achievements from the composition of products of the specific process of reaction have been progressively promoted. However, the reported studies are mainly focused on the mechanism of corrosion and reaction, conditions of corrosion occurrence, detection methods for corrosion products and corrosion prevention and treatment for bronze ware. Transmission of powdery rust has rarely been discussed. To study the process of diffusion of powdery rust of bronze, an inspection box was designed and bronze samples with powdery rust were prepared by a simulation experiment, and the growth of powdery rust was recorded in real time. Then the aerosol particles in the box were determined by inductively coupled plasma-mass spectrometry, Raman spectrometry and neocuproine-absorbance. The results show that basic cuprous chloride was the main component of bronze powdery rust and the final product of the reaction of powdery rust formation. Cuprous chloride was the intermediate product of the reaction and was converted to basic cuprous chloride in the presence of oxygen and moisture. The aerosol copper ion content in the inspection box was significantly higher than the normal value. Combined with this observation, it is shown that the powdery rust growth occurred from the inside to the outside, and that the internal reaction would make the reaction product expand, and that growth and expansion would continue outwards until cracking. The products of powdery rust were mainly composed of a mixture of cuprous chloride and basic cuprous chloride, which were fine granular, mostly loose matters. Under the splitting and breaking force, rust powder turned into a completely irregular suspended substance with the air flow and fell into the surrounding environment. When in contact with other bronzes, the powdery rust would then “infect” them upon an increase of oxygen and moisture. Compared with previous literature, this study expands in the following aspects:1) it is pioneering experimental research conducted on the diffusing process of powdery rust, and it is shown that the powdery rust grows in a process of continuous expansion from the inside to the outside until the rust layer breaks; 2) this study has found that the aerosol fine particles (cuprous chloride and basic cuprous chloride) generated in this process will become suspended in the air and then settle, causing infection; 3) based on the experimental results, some suggestions are put forward for the restoration process and preservation environment of bronzes. This study provides support for the identification of bronze rust products and evidence for understanding the transmission of powdery rust by aerodynamics. It can also be a useful reference for the prevention of bronze powder. It greatly enriches domestic research results concerning the dispersion of bronze rust powder by aerodynamics, as well as provides new insight into the study of the corrosion mechanism of bronze. Furthermore, it can also provide a feasible method to decelerate the growth and infection of powdery rust.