The invention discloses auxiliary tool for operation and provides an operation line fixing box. The fixing box comprises a box body and a box cover; the box body and the box cover form a rectangular cavity; the upper part, close to the cavity, of the box body is provided with a groove in which a ball is arranged; the wall of the cavity is provided with a protrusion and a button penetrating the cavity, and a line winding column is arranged on the other end of the cavity; the operation line passes the groove and is wound on the line winding column; and the upper part of the box cover is providewith a needle box, and the lower part is provided with an elastic sheet, The fixing box has the advantages of avoiding disorder of the operation line, facilitating the addition of the operation line in the operation, improving the nursing quality and efficiency in an operation room, keeping the operation line wet, and avoiding the cutting damage of the tissues due to the over-dry operation line; moreover, the operation needles are fixed in the needle box, a magnet on the bottom part of the needle box can attract the iron-made needles, so that the loss of the needles is avoided. Therefore, thefixing box can greatly reduce nursing risks in the operation, and improve nursing safety.