Infrared digital holography has the advantages of being less susceptible to visible light interference and low requirements for system stability,and has application value in many fields.The moisture has a strong absorption effect on the infrared light of multiple bands.Combining this characteristic with the infrared digital holography,the fresh Panax notoginseng slice is taken as the tested object.As time goes on,the moisture content on the surface gradually decreases,the absorption of the object light on the surface gradually weakens,the object light gradually increases,and the fringe contrast of the hologram changes.Through the calculation of the fringe contrast of the hologram taken in the experiment,the overall change trend is consistent with the expected moisture content change trend,which verifies the feasibility of this method.Then,the experiment of measuring moisture content by simulated near infrared method is added.The comparison of the experimental results show the superiority of the proposed method in the measurement accuracy.