A fixing clamp for a discharge outlet of intermediate bulk container provided with a discharge passage, wherein the fixing clamp is configured to be capable of fixing the discharge outlet in the discharge passage, wherein the discharge outlet comprises a discharge outlet clamping part having a polygonal structure, wherein the fixing clamp comprises: a fixing clamp body, wherein one end of the fixing clamp body is an opening end, and a passage is formed in the middle part of the fixing clamp body and is configured to accommodate the discharge outlet clamping part; clamping portions, wherein the clamping portions have profiles forming said passage of the fixing clamp body, and the clamping portions are provided such that the clamping portions are capable of clamping side surfaces of the discharge outlet when the fixing clamp and the discharge outlet have been assembled; anti-release portions (9, 12), wherein the anti-release portions (9, 12) are provided at distal ends of guiding ribs and are integrally formed with the guiding ribs, and the anti-release portions are provided with anti-release surfaces, such that when assembled, the anti-release surfaces abut against the discharge outlet clamping part to prevent the fixing clamp from being detached from the discharge outlet; characterised in that the guiding ribs are elastic, wherein the elastic guiding ribs are provided at the opening end of the fixing clamp body and are connected fixedly to the clamping portions with their proximal ends respectively, and grooves are formed between the clamping portions and the elastic guiding ribs respectively, wherein leading-in surfaces are provided on the elastic guiding ribs, and the elastic guiding ribs are provided such that the elastic guiding ribs are configured to be deformed into the grooves by the discharge outlet clamping part when the fixing clamp is pushed in laterally with respect to the discharge outlet, and the elastic guiding ribs are also provided such that the elastic guiding ribs are configured to return elastically when the fixing clamp and the discharge outlet have been assembled. a fixing clamp body, wherein one end of the fixing clamp body is an opening end, and a passage is formed in the middle part of the fixing clamp body and is configured to accommodate the discharge outlet clamping part; clamping portions, wherein the clamping portions have profiles forming said passage of the fixing clamp body, and the clamping portions are provided such that the clamping portions are capable of clamping side surfaces of the discharge outlet when the fixing clamp and the discharge outlet have been assembled; anti-release portions (9, 12), wherein the anti-release portions (9, 12) are provided at distal ends of guiding ribs and are integrally formed with the guiding ribs, and the anti-release portions are provided with anti-release surfaces, such that when assembled, the anti-release surfaces abut against the discharge outlet clamping part to prevent the fixing clamp from being detached from the discharge outlet; characterised in that the guiding ribs are elastic, wherein the elastic guiding ribs are provided at the opening end of the fixing clamp body and are connected fixedly to the clamping portions with their proximal ends respectively, and grooves are formed between the clamping portions and the elastic guiding ribs respectively, wherein leading-in surfaces are provided on the elastic guiding ribs, and the elastic guiding ribs are provided such that the elastic guiding ribs are configured to be deformed into the grooves by the discharge outlet clamping part when the fixing clamp is pushed in laterally with respect to the discharge outlet, and the elastic guiding ribs are also provided such that the elastic guiding ribs are configured to return elastically when the fixing clamp and the discharge outlet have been assembled.