The invention discloses preparation and application of an electrochemical oxygen sensor sensitive material and belongs to the technical field of electrochemistry. The preparation include the following steps that firstly, a precious metal precursor salt solution and conductive carriers are taken, the conductive carriers are dispersed into the precious metal precursor salt solution, stirring is continuously performed, and meanwhile steeping liquor is added; secondly, under the condition of 15-30 DEG C, steeping liquor is added into mixed liquid obtained in the first step, meanwhile an alkaline solution is added, the PH value of the mixed solution is adjusted to 10-11, and a loaded precious metal matter static solution is obtained; thirdly, the loaded precious metal matter static solution obtained in the second step is centrifuged, washed and dried under the vacuum condition so that dried powder can be obtained, and then the electrochemical oxygen sensor sensitive material can be obtained. Under the condition of acidic electrolyte, the sensitive material which is novel in composition is combined with an oxygen gas diffusion electrode and thus has better activity, and the sensitive material is more stable and can provide detecting and warning signals.