A pixel circuit, a drive method, a display substrate, and a display device are provided. The pixel circuit includes a light emitting device, a current supply sub-circuit, and a time control sub-circuit. The current supply sub-circuit is connected to a scanning signal terminal, a data signal terminal, a light emitting control terminal, a first power voltage terminal, the time control sub-circuit, and the light emitting device, and is configured to receive a data voltage of the data signal terminal and provide a drive current for the light emitting device. The time control sub-circuit is connected to the scanning signal terminal, a time length signal terminal, a second power voltage terminal, a direct current control signal terminal, and a direct current voltage terminal, and is configured to receive a time length voltage of the time length signal terminal and a direct current voltage input by the direct current voltage terminal.