In aquaculture operations with nets including scallop aquaculture, there exist many problems as the management of fishing gears is dependent on the traditional method that has been using the pure labor forces. These give rise to the environmental contamination and increase of total fishery costs because they prevent the fishermen from reusing the fishing gears. Due to the eco-friendly issues and aggravation of the management cost, the need to automate the washing operation of the fishing gears has been required consistently. In this study, development of scallop fishing gear washing apparatus was carried out. We conducted the preliminary experiments applying Taguchi experimental method in order to find the influential factors and optimal levels to the washing performance. Based on these result, we designed the structure and the kinematic mechanism of the fishing gear washer. Final prototype was verified to be effective in maximizing the washing rate through the performance test.