The invention discloses a carbon fiber paper and sodium polyacrylate composite conductive gel sheet and a preparation method and application thereof. The carbon fiber paper and sodium polyacrylate composite conductive gel sheet comprises a sodium polyacrylate gel sheet, first carbon fiber paper and second carbon fiber paper, and the sodium polyacrylate gel sheet is positioned between the first carbon fiber paper and the second carbon fiber paper to form a three-layer laminated structure. A conductive ionic solution is adsorbed in the sodium polyacrylate gel sheet, reactant solution of hydrogel is mixed and then arranged between the first carbon fiber paper and the second carbon fiber paper to realize polymerization reaction, or the reactant solution of hydrogel is polymerized to generate the gel sheet which is then positioned between the first carbon fiber paper and the second carbon fiber paper to obtain a composite gel sheet, and the composite gel sheet is infiltrated into the conductive ionic solution to obtain the composite conductive gel sheet. On the one hand, the carbon fiber paper in the composite conductive gel sheet is capable of improving mechanical strength of the gel sheet; on the other hand, the carbon fiber paper which is conductive improves conductivity of the gel sheet together with conductive ions in the gel sheet.