Variable pump load-sensitive and constant-pressure switching control system and control method

The invention discloses a variable pump load-sensitive and constant-pressure switching control system and method. The variable pump load-sensitive and constant-pressure switching control system comprises a multi-way valve and a switching valve set. The switching valve group comprises a reversing valve, a first hydraulic control one-way valve and a shuttle valve; on-off of the first hydraulic control one-way valve is controlled through the reversing valve switching station, so that switching between a constant-pressure working mode and a load-sensitive working mode is achieved. According to the control method, the working modes of the variable pump are switched through the reversing valve, the variable pump can be continuously kept in the corresponding working state only by switching the variable pump to the corresponding working position in the process of switching the working modes of the pump, specifically, when the reversing valve is switched to the upper position once, the variable pump is in the constant