Abstract: Volume-fracturing in unconventional reservoirs needs massive fluid and brings plenty of flow-back fluid which contains varied ions, residual additives, suspending matters and so on, so harmless disposal has great difficulties. This paper introduced the ways of disposal flow-back fluid from volume-fracturing, and combined the actual circumstance of unconventional gas well in Sichuan. We formed the disposal flow-back fluid process. Laboratory study showed that concentration of residual additives were low in flow-back fluid, but had a certain amount of total dissolved salts, the drag friction of the treated flow-back fluid was the same as the fracturing fluid produced by the freshwater. It also came to the same conclusion in field trial, which gained efficient reservoir reformation, saved freshwater, reduced drainage of waste water, and achieved energy conservation and emission reduction.