The urban heat island effect is worsening with the rapid urbanization of Beijing. Vehicle heat emissions are regarded as one of the most significant factors affecting the urban thermal environment. The intensity and scale of the impact of vehicle heat should not be ignored given the sharp increase in car ownership in recent years. Taking the region inside Beijing 5^th ring road as the study area, this paper proposes a feasible method to calculate vehicle heat intensity through the data of transportation index, traffic density, road length, etc. The microclimate data were collected through field sampling at several typical sites. These temperature and humidity data were used to explore the quantitative relationship with vehicle heat intensity in the Beijing metropolis. The results show that vehicle heat intensity distributes in radial pattern in Beijing. The mean heat intensity ranges from 8.6 to 10.8 W/m² and reaches 32.2-53.9 W/m² inside the 3th ring road. The average vehicle heat intensity at daytime is 2-10 times the intensity at nighttime. The maximum value of vehicle heat appears in the mornings and evenings. Interestingly, the spatial pattern of vehicle heat has no significant difference between weekends and weekdays. The vehicle heat intensity at 8:00 a.m. shows a significant correlation with its temperature difference on main roads. The temperature amplification reaches 0.91℃/10 W/m² at 8:00 a.m. At some points, we observe a significantly positive correlation between vehicle heat intensity and its temperature difference. We also notice a lag effect (10-20 min) of vehicle heat on temperature amplification. This study could provide useful information for the scientific planning of roads and urban landscapes.