A floor cleaner, comprising: a cleaning roller for floor cleaning, a water channel that is configured to cover the cleaning roller with an airtight seal, a clean water tank that is configured to store clean water, a clean water supply system, wherein the clean water tank, the clean water supply system and the water channel are in communication with each other, and wherein the clean water supply system is configured to allow clean water in the clean water tank to flow to the water channel, a wastewater tank, wherein the wastewater tank comprises a chamber for recovery and store of wastewater, and wherein the chamber is provided with a wastewater inlet and an air extraction opening; and wherein the wastewater inlet and the water channel are in communication, and an air pump, wherein an inlet of the air pump and the air extraction opening of the wastewater tank are in communication; characterized in that the chamber of the wastewater tank is provided with a splash-proof member comprising a first buffer chamber, the first buffer chamber being provided with a first air vent and a second air vent on an upper and a lower end respectively, wherein the first air vent and the second air vent are arranged with different directions; wherein the splash-proof member is configured to divide the wastewater tank into an accommodation chamber and a second buffer chamber, wherein the second buffer chamber is provided with the air extraction opening; wherein the accommodation chamber and the first buffer chamber are in communication through the second air vent and the second buffer chamber and the first buffer chamber are in communication through the first air vent; and wherein at least two among the air extraction opening, first air vent and the second air vent have an offset arrangement. a cleaning roller for floor cleaning, a water channel that is configured to cover the cleaning roller with an airtight seal, a clean water tank that is configured to store clean water, a clean water supply system, wherein the clean water tank, the clean water supply system and the water channel are in communication with each other, and wherein the clean water supply system is configured to allow clean water in the clean water tank to flow to the water channel, a wastewater tank, wherein the wastewater tank comprises a chamber for recovery and store of wastewater, and wherein the chamber is provided with a wastewater inlet and an air extraction opening; and wherein the wastewater inlet and the water channel are in communication, and an air pump, wherein an inlet of the air pump and the air extraction opening of the wastewater tank are in communication; characterized in that the chamber of the wastewater tank is provided with a splash-proof member comprising a first buffer chamber, the first buffer chamber being provided with a first air vent and a second air vent on an upper and a lower end respectively, wherein the first air vent and the second air vent are arranged with different directions; wherein the splash-proof member is configured to divide the wastewater tank into an accommodation chamber and a second buffer chamber, wherein the second buffer chamber is provided with the air extraction opening; wherein the accommodation chamber and the first buffer chamber are in communication through the second air vent and the second buffer chamber and the first buffer chamber are in communication through the first air vent; and wherein at least two among the air extraction opening, first air vent and the second air vent have an offset arrangement.