The invention provides a waste gas treatment device of a leather workshop and belongs to the technical field of waste gas treatment, aiming at solving the technical problems that discharging effect of waste gas in an existing workshop is not good and the like. The waste gas treatment device of the leather workshop is characterized by comprising a gas collection cover with an inverted funnel shape; the top of the gas collection cover is connected with a gas collection barrel; a gas inlet of the gas collection barrel is communicated with a top opening of the gas collection cover; a gas outlet of the gas collection barrel is fixed with the bottom of a gas outlet barrel and is communicated with an inner cavity of the gas outlet barrel; the top of the gas outlet barrel is connected with a first gas conveying pipe which is communicated with the inner cavity of the gas outlet barrel; the other end of the first gas conveying pipe is connected with a waste gas purification device through a pipeline; the waste gas purification device is connected with an exhausting device through a second gas conveying pipe; the gas collection cover is internally further provided with an exhausting device which is used for sucking air below the gas collection cover into the gas collection cover. The waste gas treatment device of the leather workshop has the advantages of good effects of treating waste gas in the workshop and small environment pollution.