You can get to Thaling Chan Floating market bus 79 or 83 (about one hour - around 20 THB). These buses drops you 10 meters from the entrance. Otherwise Dark Red Line connected to MRT subway at Bang Sur station is also a good option to go to this floating market in Bangkok. Taling Chan station is around 1 kilometer from the market entrance.
There is also a train station not far but still about 2 km away.
Note that since January 2023, there is a free bus line serving Taling Chan floating market and 3 other floating markets in Bangkok. You can find all the information on these
free buses to Taling Chan Floating Market here.