Intelligent integrated excation in coal mine tunnels is a crucial research focus in the global coal mining industry, with significant implications for achieving safe and efficient extraction in deep coal mining operations. The boom-type roadheader, which serves as the primary equipment for underground excavation, currently faces a critical technological challenge: the precise positioning of its key nodes. Aiming to address the low positioning accuracy and poor robustness of roadheaders currently, an improved time difference of arrival (TDOA) fusion positioning algorithm based on regularized constrained total least squares (RCTLS) and alternating direction method of multiplier (ADMM) is proposed. Meanwhile, a positioning system of roadheader in tunnel based on ultra-wide band (UWB) is constructed. Considering the analytical TDOA algorithm easliy falls into the local optima due to the ranging error, a closed-form solution of analytics is selected as the initial value of ADMM, and the objective function is iteratied via dual auxiliary variables to achieve the positioning. The experimental result indicates that the RCTLS-ADMM enhances positioning accuracy by reducing the average positioning error of X, Y and Z axes from 0.159 m, 0.154 m, and 0.167 m to 0.139 m, 0.133 m, and 0.141 m, and improves the positioning accuracy by 12.57%, 13.64% and 15.57% respectively in long-narrow environments if the UWB ranging error is non-negligible. The positioning strategy of roadheader provides the significant parameters for achieving self-dominant control of roadheader and has practical applicated value.