A wearable and hidden breast pump includes a shell, a flange, a negative pressure chamber, a negative pressure pump, a milk container and a solenoid valve. The flange is arranged on a front surface of the shell; the negative pressure chamber is arranged in the shell and connected with the flange to form an lactation chamber; the negative pressure pump and the solenoid valve are arranged in the shell, the negative pressure pump, the solenoid valve and the negative pressure chamber are communicated; the negative pressure pump intermittently extracts air from the negative pressure chamber, and the solenoid valve intermittently inflates air into the negative pressure chamber, thus controlling an air amount in said negative pressure chamber, thereby controlling the lactation chamber to form a negative pressure or a positive pressure; the milk container is arranged under the shell and communicated with the lactation chamber.