The invention relates to a method for measuring moisture content gradient in a drying process of woods and a measuring sensor used for the method. The method for measuring moisture content gradient in the drying process of woods includes: in the drying process of the woods, inserting a measuring sensor into the woods for measuring resistance within a certain distance in the width direction of two different-thickness layers of the woods on line, calculating the moisture content rate of the different-thickness layers of the woods according to the resistance and then calculating the moisture content gradient of the woods according to the moisture content ratio and the distance between the different-thickness layers. Due to the method, in the drying process of the woods, operating staff can calculate the moisture content gradient and moisture content deviation on the thickness by measuring the moisture content ratio of the two-layer or multiple-layer woods on line on the basis of easy and safe operation, softness or hardness of drying standard can be judged according to the moisture content gradient, temperature and humidity of the drying medium can be adjusted timely, and accordingly the aim for improving drying quality and shortening drying cycle can be achieved.