Background The health effects of forest therapy have been widely recognized, while the previous studies mostly focused on a single activity mode of forest walks. The effects of different types of forest therapy activities remain unclear. Objective To explore the effects of short-term forest therapy on cardiopulmonary health, psychological health, and sleep quality, and the health effects of different types of forest therapy activities, aiming to provide population empirical study data for the development of forest therapy. Methods A self-control study was conducted in a national forest park in suburb of Beijing from August to September 2018. A total of 31 healthy college students were recruited as the study subjects, with a total forest stay for 3 days and 2 nights. During the period of study, each subject practiced walking therapy, sitting therapy with five senses experience (sitting therapy thereafter), and handmade work therapy, successively. Each type of forest therapy lasted about 2 h. Changes of blood pressure, oxygen saturation (SpO₂), lung function, and fractional exhaled nitric oxide (FeNO) were estimated by measuring corresponding indicators before and after the forest therapy. Psychological health and sleep quality were assessed by Profile of Mood States and Pittsburgh Sleep Quality Index respectively at the same time. Mixed effects models were used to analyze the changes of these health indicators. The health effects of different types of forest therapy activities were further analyzed. Results The average age and body mass index of subjects in this study were (24.5±2.6) years and (20.7±1.7) kg·m⁻², respectively. After a short-term forest therapy, the selected indicators of cardiopulmonary health, psychological health, and sleep quality of subjects were all improved. In particular, the pulse pressure (PP) and FeNO decreased by 3.02 mmHg and 1.10 ppb, respectively, while the SpO₂ and peak expiratory flow (PEF) increased by 0.65% and 0.50 L·s⁻¹, respectively, and the negative emotion and global sleep quality also presented significant positive changes (all P<0.05). Furthermore, different therapy activities presented differential effects in the health indicators. Walking therapy significantly improved pulmonary function, SpO₂, and confusion (CON) emotion, in which the SpO₂, forced expiratory volume in the first second (FEV₁), and forced vital capacity (FVC) increased by 0.48%, 0.14 L, and 0.12 L, respectively, and the score of CON decreased by 0.97 (all P<0.05). Sitting therapy significantly reduced blood pressure and tension (TEN) emotion of subjects, including a decrease of the systolic blood pressure (4.45 mmHg), PP (4.19 mmHg), and the score of TEN (0.84) (all P<0.05). The diastolic blood pressure (DBP) increased slightly after handmade work therapy (ΔDBP=2.44 mmHg, P=0.016), but there were no significant changes in other indicators. Conclusion Short-term forest therapy could significantly improve cardiopulmonary health, psychological health, and sleep quality of young healthy individuals, and different types of forest therapy activities may have differential health effects.