admin_batch_upload.py

class AlbumAdminForm(forms.ModelForm):
    photos_batch = forms.FileField(
        widget=forms.FileInput(attrs={
            'accept': 'image/png, image/jpeg',
            'multiple': True,
        }),
        required=False,
        label='Photos',
        help_text='Choose multiple files.',
    )

    class Meta:
        model = Album
        fields = '__all__'


@admin.register(Album)
class AlbumAdmin(admin.ModelAdmin):
    form = AlbumAdminForm
    
    def save_related(self, request, form, formsets, change):
        super().save_related(request, form, formsets, change)
        photos_batch = request.FILES.getlist('photos_batch')
        for photo in photos_batch:
            form.instance.photos.create(image=photo)