The invention discloses an underground while-drilling double-geological-parameter measuring instrument overall cascading method. An independent domestic turbine generator short joint and an independent domestic pulse generator short joint are used for replacing an imported integrated short joint of an imported turbine generator and an imported pulse generator, and the domestic pulse generator short joint is moved to the bottom from the overall cascading upper portion. The domestic turbine generator short joint, a directional measuring short joint, a gamma measuring short joint, a cavity wall conversion connector, a resistance rate short joint, a wall cavity conversion connector and the domestic pulse generator short joint are sequentially cascaded from top to bottom. By means of the underground while-drilling double-geological-parameter measuring instrument overall cascading method, the domestic short joint is used for replacing the imported short joint, and the instrument study cost is reduced; special maintenance equipment needing to be matched with the imported short joint is omitted, and the daily maintenance difficulty and use cost are lowered; the domestic pulse generator ishigh in adaptability to domestic well drilling liquid, and the service cycle is prolonged by nearly three times; and the instrument use rate is increased, low-cost running is achieved; and the requirement for oil drilling is met.