A weft detection sensor is provided that detects a passage of a weft to determine a passage timing of a weft circulating around a storage drum, and a weft insertion method includes setting in advance a reference value of a set position arrival timing in association with a set arrival position, regarding the set arrival position and the set position arrival timing at which a leading edge of the weft reaches the set arrival position, and determining an actual value of the set position arrival timing from the passage timing determined in weft insertion during weaving, comparing the actual value with the reference value, and in a case where a deviation occurs between the actual value and the reference value, determining a correction amount of a set value of a weft insertion related device based on the deviation so that the deviation decreases.