The distance between Qianmen and niujie is about 7 kilometers, and it takes about 15-2 minutes by car. From Qianmen to niujie, it is suggested to choose the following modes of transportation:

1. Subway: Take subway line 7 from Qianmen Station to Guangqumennei Station, and then transfer to subway line 5 to Niujie Station. The whole journey takes about 4 to 5 minutes, and the fare is generally around 4 yuan.

2. Bus: Take Bus No.48 from Qianmen to Yongdingmen, and then transfer to Bus No.77 to Niujie Station. The whole journey takes about 3 to 4 minutes, and the fare is generally around 2 yuan.

3. Taxi: It takes about 15-2 minutes to get to niujie from Qianmen, and the taxi fare is about 2 yuan. The specific fare is also affected by travel time and road conditions.

It should be noted that there are many food stalls around niujie, which is a famous food street. There is a large flow of people, and it is crowded to get in and out. It is necessary to plan the traffic in advance so as not to delay time.