A method for erasing handwriting on an electronic whiteboard, comprising: obtaining first contact points; and enabling an erasing mode when a quantity of the first contact points is greater than a preset value; obtaining second contact points in the erasing mode, and calculating an erasing region according to the first contact points and the second contact points; and deleting handwriting data in the erasing region; wherein the calculating an erasing region according to the first contact points and the second contact points specifically comprises: generating contact point variables, wherein the contact point variables comprise quantity information and position information of contact points in the erasing mode; and calculating a convex polygonal erasing region according to the contact point variables by using a convex hull algorithm; wherein the deleting handwriting data in the erasing region specifically comprises: dividing handwriting into a plurality of geometric figures; and determining whether the geometric figure intersects with the convex polygon; and deleting handwriting data of the geometric figure when the geometric figure intersects with the convex polygon; and the determining whether the geometric figure intersects with the convex polygon comprises: upon detecting that a line segment forming the handwriting intersects with any edge of the convex polygon, determining that the line segment intersects with the convex polygon. obtaining first contact points; and enabling an erasing mode when a quantity of the first contact points is greater than a preset value; obtaining second contact points in the erasing mode, and calculating an erasing region according to the first contact points and the second contact points; and deleting handwriting data in the erasing region; wherein the calculating an erasing region according to the first contact points and the second contact points specifically comprises: generating contact point variables, wherein the contact point variables comprise quantity information and position information of contact points in the erasing mode; and calculating a convex polygonal erasing region according to the contact point variables by using a convex hull algorithm; wherein the deleting handwriting data in the erasing region specifically comprises: dividing handwriting into a plurality of geometric figures; and determining whether the geometric figure intersects with the convex polygon; and deleting handwriting data of the geometric figure when the geometric figure intersects with the convex polygon; and the determining whether the geometric figure intersects with the convex polygon comprises: upon detecting that a line segment forming the handwriting intersects with any edge of the convex polygon, determining that the line segment intersects with the convex polygon. generating contact point variables, wherein the contact point variables comprise quantity information and position information of contact points in the erasing mode; and calculating a convex polygonal erasing region according to the contact point variables by using a convex hull algorithm; wherein the deleting handwriting data in the erasing region specifically comprises: dividing handwriting into a plurality of geometric figures; and determining whether the geometric figure intersects with the convex polygon; and deleting handwriting data of the geometric figure when the geometric figure intersects with the convex polygon; and the determining whether the geometric figure intersects with the convex polygon comprises: upon detecting that a line segment forming the handwriting intersects with any edge of the convex polygon, determining that the line segment intersects with the convex polygon. dividing handwriting into a plurality of geometric figures; and determining whether the geometric figure intersects with the convex polygon; and deleting handwriting data of the geometric figure when the geometric figure intersects with the convex polygon; and the determining whether the geometric figure intersects with the convex polygon comprises: upon detecting that a line segment forming the handwriting intersects with any edge of the convex polygon, determining that the line segment intersects with the convex polygon.