Is there any tool help you "bend" object?

Is there any tool help you "bend" object? i try to make an arc object from a cylinder and no luck, can anyone help me?

You can use this tool, vertex mode > Spline Modify. Once the tool is activated, choose menu 'Help > Show Help On Current Operation' to bring up the help file so you can read through the information about how to use this tool.

Thank for the information, i try the help but no use, it is so confuse. In the help, how they make the spline curve with just 2 point?

You can use the spline creation tools to create splines, object mode > Create > Create Spline. Once you have created the spline, while the spline is selected, go to vertex mode and you will see some spline related tools in the 'Visual Tools' panel.