You can use the sum in the QueryBuilder.

像这样：

$data = ProjectHistory::where('id', 1)->sum('suma');

In your case, you may also use the withSum to obtain the result you want. Like so:

$data = Collaborator::withSum('ProjectHistory', 'suma')->get();

This resulting Collaborator will have an extra key now named: projecthistory_sum_suma which will have the sum of all the suma belonging to that Collaborator.

This of course assumes that you have a hasMany relation with the ProjectHistory model.