A production method for a liquid ejection head having a structure in which a plurality of head modules are arranged along a single direction, each of the plurality of head modules including a plurality of ejection elements, the liquid ejection head production method comprising: a first head module setting step of setting a first head module; a second candidate head module selection step of selecting a second candidate head module, the second candidate head module being a candidate for a second head module, the second head module being arranged at a position that is adjacent to the first head module; a first representative value acquisition step of acquiring a first representative value, the first representative value being a representative value of ejection volumes of ejection elements that are included in the first head module and that are arranged at a joint part between the first head module and the second head module; a second representative value acquisition step of acquiring a second representative value, the second representative value being a representative value of ejection volumes of ejection elements that are included in the second candidate head module and that are arranged at the joint part; an average value derivation step of deriving an average value of the first representative value and the second representative value; and a setting step of setting, as the second head module, the second candidate head module by which the average value derived in the average value derivation step is 0.76-fold or more and 1.24-fold or less of an average ejection volume target value, the average ejection volume target value being a previously decided target value of an average ejection volume in a whole of the liquid ejection heat. a first head module setting step of setting a first head module; a second candidate head module selection step of selecting a second candidate head module, the second candidate head module being a candidate for a second head module, the second head module being arranged at a position that is adjacent to the first head module; a first representative value acquisition step of acquiring a first representative value, the first representative value being a representative value of ejection volumes of ejection elements that are included in the first head module and that are arranged at a joint part between the first head module and the second head module; a second representative value acquisition step of acquiring a second representative value, the second representative value being a representative value of ejection volumes of ejection elements that are included in the second candidate head module and that are arranged at the joint part; an average value derivation step of deriving an average value of the first representative value and the second representative value; and a setting step of setting, as the second head module, the second candidate head module by which the average value derived in the average value derivation step is 0.76-fold or more and 1.24-fold or less of an average ejection volume target value, the average ejection volume target value being a previously decided target value of an average ejection volume in a whole of the liquid ejection heat.