An embodiment of the present description provides a decoding method and device for a quantization block as well as an electronic device. The method comprises: determining the scanning order of quantization coefficients in the quantization block, initializing the scanning position of the quantization coefficients, and decoding a run-length; adding a subscript value of the current scanning position and the value of the run-length to obtain the scanning position of nonzero coefficients, decoding the values of the nonzero coefficients; judging whether the subscript value of the nonzero coefficients is the maximum subscript value, if yes, ending the decoding of the quantization block; if not, judging whether there are undecoded nonzero coefficients, and if there are no undecoded nonzero coefficients, ending the decoding of the quantization block; if there are undecoded nonzero coefficients, adding 1 to the subscript value of the decoded nonzero coefficients to obtain an updated current scanning position, taking the current scanning position as the initial scanning position to decode the next run-length until the decoding of the quantization block is completed. The technical solution of the present application can improve the decoding efficiency of quantization block.