A hot test device for a control rod drive line, comprising a bottom connecting shell, a lower pressure shell, a middle pressure shell, an upper pressure shell, a lower core plate, a baffle assembly, and an upper core plate, a guide tube support plate, a guide tube, a tube base installation structure and a tube base, characterized in that, the bottom connecting shell, the lower pressure shell, the middle pressure shell, and the upper pressure shell are sealed and connected in sequence, a lower plate installation notch and an upper plate installation notch are respectively formed at two ends of the lower pressure shell, and the lower core plate is fixed on the lower plate installation notch; a plurality of baffle adjusting members arranged in a circumferential direction are provided at a position close to a top of the baffle assembly; in virtue of adjustments to the baffle adjusting members, and abutments between the baffle adjusting members and an inner side wall of the lower pressure shell, the baffle assembly is centered relative to the lower core plate; the upper core plate is fixed at the upper plate installation notch, a plurality of upper plate adjusting members arranged in a circumferential direction are provided at the upper core plate, in virtue of adjustments to the upper plate adjusting members, and abutments between the upper plate adjusting members and an inner side wall of the upper plate installation notch, the upper core plate is centered relative to the lower core plate; an upper end of the middle pressure shell is formed with a support plate installation notch on which the guide tube support plate is fixed, a plurality of support plate adjusting members arranged in a circumferential direction are provided at the guide tube support plate, in virtue of adjustments to the support plate adjusting members, and abutments between the support plate adjusting members and an inner side wall of the support plate installation notch, the guide tube support plate is centered relative to the lower core plate; and the tube base installation structure is placed on an upper end of the upper pressure shell. characterized in that, the bottom connecting shell, the lower pressure shell, the middle pressure shell, and the upper pressure shell are sealed and connected in sequence, a lower plate installation notch and an upper plate installation notch are respectively formed at two ends of the lower pressure shell, and the lower core plate is fixed on the lower plate installation notch; a plurality of baffle adjusting members arranged in a circumferential direction are provided at a position close to a top of the baffle assembly; in virtue of adjustments to the baffle adjusting members, and abutments between the baffle adjusting members and an inner side wall of the lower pressure shell, the baffle assembly is centered relative to the lower core plate; the upper core plate is fixed at the upper plate installation notch, a plurality of upper plate adjusting members arranged in a circumferential direction are provided at the upper core plate, in virtue of adjustments to the upper plate adjusting members, and abutments between the upper plate adjusting members and an inner side wall of the upper plate installation notch, the upper core plate is centered relative to the lower core plate; an upper end of the middle pressure shell is formed with a support plate installation notch on which the guide tube support plate is fixed, a plurality of support plate adjusting members arranged in a circumferential direction are provided at the guide tube support plate, in virtue of adjustments to the support plate adjusting members, and abutments between the support plate adjusting members and an inner side wall of the support plate installation notch, the guide tube support plate is centered relative to the lower core plate; and the tube base installation structure is placed on an upper end of the upper pressure shell.