diff --git a/apollo.sh b/apollo.sh
index 60a2cc684fbad3813daa3dd4c27b6edb34427a40..b40592771e3e39e96b2296b39e63e6be9061a9e8 100755
--- a/apollo.sh
+++ b/apollo.sh
@@ -121,7 +121,7 @@ function _usage() {
   ${BLUE}build_teleop${NO_COLOR}: run build with teleop enabled.
   ${BLUE}build_prof [module]${NO_COLOR}: build with perf profiling support. Not implemented yet.
   ${BLUE}doc${NO_COLOR}: generate doxygen document
-  ${BLUE}clean${NO_COLOR}: cleanup, including 'bazel clean --async'.
+  ${BLUE}clean${NO_COLOR}: cleanup bazel outputs and log/coredump files
   ${BLUE}usage${NO_COLOR}: show this message
   "
 }
diff --git a/scripts/apollo_clean.sh b/scripts/apollo_clean.sh
index 764b487ffe9f614fadbd35d3cfafd1d4dc1b5f2d..44a2eeb9092318c034dcf9276b9fe80d7a530931 100755
--- a/scripts/apollo_clean.sh
+++ b/scripts/apollo_clean.sh
@@ -26,16 +26,16 @@ LOG_DIR="${TOP_DIR}/data/log"
 
 function _clean_cache() {
   local opt="--async"
-  if [ "$1" == "expunge" ]; then
+  if [ "$1" == "--expunge" ]; then
     opt="--expunge_async"
   fi
 
-  bazel clean "${opt}"
+  bazel clean ${opt}
 
   # Remove bazel cache in associated directories
   if [ -d /apollo-simulator ]; then
     pushd /apollo-simulator > /dev/null
-    bazel clean "${opt}"
+    bazel clean ${opt}
     popd > /dev/null
   fi
 }
@@ -64,9 +64,20 @@ function _clean_docs() {
   fi
 }
 
-function clean() {
+function _print_usage() {
+  echo -e "Usage:\n  $0 [options]\nOptions:"
+  echo "${TAB}--expunge   Run \"bazel clean --expunge\""
+  echo "${TAB}-h, --help  Show this message"
+}
+
+function main() {
+  if [ "$1" = "-h" ] || [ "$1" = "--help" ]; then
+    _print_usage
+    exit 1
+  fi
+
   if ! "${APOLLO_IN_DOCKER}"; then
-    error "The clean operation must be run from within docker container"
+    error "The clean operation should be run from within docker container"
     exit 1
   fi
 
@@ -76,9 +87,10 @@ function clean() {
 
   local answer
   typeset -l answer
-  warning "All the files under ${LOG_DIR} and ${CORE_DIR} will be removed."
-  warning "Do you want to continue (Y/n)?"
+  warning "Do you want to remove all log files under \"${LOG_DIR}\"" \
+    "and core dump files under \"${CORE_DIR}\" (Y/n)?"
   answer=$(read_one_char_from_stdin)
+  info "Your choice is: ${answer}"
   if [ "${answer}" == "y" ]; then
     _clean_core
     _clean_log
@@ -87,8 +99,4 @@ function clean() {
   success "Apollo cleanup done."
 }
 
-function main() {
-  clean "$@"
-}
-
 main "$@"