Is there a train from China to Russia?

Yes It's the K3/4 international train, Beijing-Ulan Toba-Moscow, which takes about six days.

Among them, Beijing-Moscow departs from Beijing Station every Wednesday, runs 13 1 hour 3 1 minute, and arrives at Yaroslavl Station in Moscow on Monday with trains K3 (domestic), 003 (Mongolia) and 0033 (Russia); Moscow to Beijing departs from Yaroslavl Station in Moscow every Tuesday, runs 129 hours and 40 minutes, and arrives at Beijing Station on Monday. The trains used are K4 (China), 004 (Mongolia) and 0043 (Russia).

Extended data:

1On June 4th, 959, the Beijing-Ulaanbaatar-Moscow international passenger train officially started, and the number of trains was determined to be 3/4. Soviet railways provided vehicles and served as crew members. After leaving Beijing Station, the train runs on Fengsha and Beijing-Baotou lines, and the bogie of the train is replaced at Jining Station. On May 24th, 1960, the Beijing-Ulaanbaatar-Moscow international passenger train, which was provided by China Railway and served as the crew, started and the train served by Soviet Railway stopped.

Domestic trains are grouped with 15 cars, and 1 soft sleeper cars will be cancelled from May, 2065. At present, the international combined transport vehicles are grouped into 7 hard sleeper cars, 2 advanced soft sleeper cars and 1 baggage cars, and 3 hard sleeper cars and 1 dining cars are from Beijing to Erlian.

References:

K3 Train-Baidu Encyclopedia