Add data to people picker in Visual webpart programatically - sharepoint 2010

Add the People picker field in the ascx file as below

 <SharePoint:PeopleEditor runat="server" ID="peoplePickerID" MultiSelect="true" 
SelectionSet="User" />

in the code behind on page load write the logic to fill teh people picker from a list having a
people/group type column.


ArrayList PickerEntities = new ArrayList(); 
SPFieldUserValueCollection fieldUserValueCollection = (SPFieldUserValueCollection)item["PeopleGroupTypeColumnDispName"];

            foreach (SPFieldUserValue spuserval in fieldUserValueCollection)
            {
                SPUser userToassign = spuserval.User;
                PickerEntity entity = new PickerEntity();
                PeopleEditor pepEditor = new PeopleEditor();
                entity.EntityData["AccountName"] = spuserval.User.LoginName;
                entity.EntityData["SPUserID"] = spuserval.User.ID;
                entity.EntityData["Email"] = spuserval.User.Email;
                entity.Key = spuserval.User.LoginName;
                entity.Description = spuserval.User.LoginName;
                entity.DisplayText = spuserval.User.Name;
                entity = pepEditor.ValidateEntity(entity);
                entity.IsResolved = true;
                PickerEntities.Add(entity);
            }

peoplePickerID.UpdateEntities(PickerEntities);

 *item["PeopleGroupTypeColumnDispName"];--> is list column of people/group type


Have a look at other post about client people picker of Sharepoint 2013
Client people picker-Sharepoint 2013