With some mistake, I lost my iPhone photos that I couldn't get them retrieved. I don't know what to do, so i search google for "photo recovery software".
Fortunately, i found iPhone Data Recovery can recover deleted photos from iphone. Here are the step to recover deleted photos on iPhone.
Step 1. Launch the free photo recovery software and connect iPhone to computer
For iPhone 6/6 Plus/5S/5C/5/4S users: After connecting your device to the computer. click the "Start Scan" button to to scan your iPhone or iOS device.
For iPhone 4/3GS users: Connect iPhone, then you can get a deeper scan after choosing "Advanced Mode" at the corner of the window.
Step 2. Preview and recover photos from iphone
After the scanning, you can preview your iPhone data on the interface. Click "Recover" button to retrieve deleted photos to pc or recover photos from iphone.
By the way, you can restore deleted photos by extracting itunes backup or retrieve lost iPhone photos from iCloud backup too.