Can the public security bureau find the content of mobile phone short messages?

The public security bureau can find out the content of the message.

Article 148 of the Criminal Procedure Law stipulates that public security organs may, after filing a case, take technical investigation measures against crimes endangering national security, terrorist activities, organized crimes of underworld nature, major drug crimes or other crimes seriously endangering society after strict approval procedures according to the needs of investigating crimes.

After filing a case, the people's procuratorate may, according to the needs of investigating crimes and through strict approval procedures, take technical investigation measures for major cases of corruption and bribery and major cases of serious violations of citizens' personal rights committed by taking advantage of their powers, and hand them over to relevant organs for execution in accordance with regulations.

To hunt down a criminal suspect or defendant who is wanted at large or whose arrest has been approved, the necessary technical investigation measures may be taken upon approval.