Threshing is the removal of stalks and husks from the seeds, which can be done either traditionally or mechanically. One of the mechanical types is the Melkassa multi -crop thresher. When using it, the feeding process is labor intensive, high drudgery and stress on the labor during biomass feed.The aim of this study was to develop a feed conveyor and test the performance of the Melkasa multi -thresher machine at Melkassa. The feed conveyor consists of a supporting frame, bearings, rotating belts, pulleys, a side cover, a lower hopper, and V-belts. Split plot design with main plot, conveyor slope, and subplot is the conveyor speed is used to examine the influence of conveyor on maize sheller. The randomized complete design is used to know the effect of feeding two treatments. These are feeding without conveyor and with conveyor to analyze the economic cost of the machine. Performance evaluation in terms of the threshing capacity, efficiency, seed breakage, fuel consumption, and labor requirement. The tests were carried out four times, and test materials weighing 200 kg of biomass were used for each treatment. The tests were carried out on a Melkassa maize sheller, with maize (variety: Melkasa-II) and multi -crop threshing with sorghum (variety: Melkam) being the test crops. The maize crop had a moisture content of 12.3 percent, while the sorghum was at 12.5%. The maximum shelling capacity of shellers is 7500.8 kg/hr at conveyor speed 400 rpm and slope 20 0 and the minimum shelling is 6440.9 kg/hr at conveyor speed 300 rpm and slope 30 0 . To analysis economic cost of conveyor using conveyor and without conveyor the sheller and thresher performance was evaluated. The capacity of the sheller is 7518 kg per hour, with a fuel consumption of 2.685 liters per hour when feedi ng with a conveyor, and 6248 kg per hour and 2.0678 liters per hour without conveyor feeding. For multi crop threshing feeding with a conveyor for the sorghum variety, the threshing capacity was 1838.49 kg/hr, and fuel consumption was 1.575 liters per hour without conveyor feed and 1290.47 kg/hr and 1.1575 liters per hour with manual feed. During shelling operations, the seed breakage is fed to the conveyors at 0.21% and 0.22% without conveyor feed. For multi-crop threshing the seed breakage is 0.18% with a conveyor and 0.19% without conveyor on sorghum. Using a feed conveyor can increase threshing capacity, reduce drudgery, save time and energy, reduce risk, and is the best way to feed the harvested crop. Key words: Design, Development, Feed Conveyor, Performance evaluation