Due to Apple's policy,It will appear when you first install the enterprise application in IOS system"Untrusted enterprise developers"Tips
The solution is as follows(Take ios11 system as an example):
1、Turn on settings in your phone,choice"currency"
2、In general,choice"Description document and equipment management"function
3、In the enterprise application classification of description document and equipment management,Select the file name of the enterprise application to install(Consistent with the prompt when opening),Click to enter
4、After entering the enterprise signature page,After confirming the company name and application name in the enterprise signature,Click trust"Enterprise signature company name"