Abstract: Wireless network planning and optimization for mine mobile communication, Internet of Things communication, and personnel and vehicle positioning systems all require the calculation of wireless transmission path loss. However, no statistical calculation method is currently available that is specifically designed for mine wireless transmission path loss under the special conditions of underground confined spaces. Existing general-purpose, open-space, and indoor wireless transmission path loss statistical calculation methods do not consider underground-specific environmental factors such as roadway cross-sectional area, making them difficult to apply directly to complex underground conditions. To address these problems, this study analyzed the main factors affecting mine wireless transmission path loss and proposed a mine wireless transmission path loss calculation method based on roadway cross-sectional area. The method considered both line-of-sight and non-line-of-sight transmission, and was related not only to frequency and distance but also to roadway cross-sectional area, curved roadways, branch roadways, belt conveyors, and roadway wall smoothness. Based on measured data, the characteristics of mine wireless transmission were revealed as follows: ① Mine wireless transmission had a significant frequency band-pass characteristic, with a frequency turning point. When the operating frequency was lower than the frequency turning point, the roadway strongly affected wireless transmission, path loss was high, and the lower the operating frequency, the greater the influence of the roadway on wireless transmission; when the operating frequency was higher than the turning point, the influence of the roadway on wireless transmission was small, but wireless transmission path loss increased as the operating frequency increased. For straight roadways, the frequency turning point occurred around 700/800 MHz. ② Wireless transmission path loss in mine roadways was greatly affected by roadway cross-sectional area. Smaller roadway cross-sections resulted in higher wireless transmission path loss, and the influence became even greater when the operating frequency was lower than the frequency turning point. ③ Wireless transmission in mine curved and branch roadways was affected both by roadway cross-sectional area and by the frequency of non-line-of-sight wireless transmission, and the influence of frequency on wireless transmission in curved and branch roadways was greater than the influence of roadway cross-sectional area. Curved roadways and branch roadways increased wireless transmission path loss in mines. The proposed method was applied to calculate wireless transmission path loss in different mine scenarios. The results showed that it achieved an average absolute error of 3.8 dB, reducing the error by 7.0, 3.3, 2.7, 5.2, 2.9, 3.5, and 5.1 dB compared with the FSPL, CIF, ABG, WINNER II, ITU-R M.2412, 3GPP InH-Office, and ITU-R P.1238 calculation methods, respectively.