diff --git a/kernel/driver/timers/HPET/HPET.c b/kernel/driver/timers/HPET/HPET.c
index 6641946d..2a79b1c2 100644
--- a/kernel/driver/timers/HPET/HPET.c
+++ b/kernel/driver/timers/HPET/HPET.c
@@ -164,7 +164,7 @@ void HPET_enable()
     apic_make_rte_entry(&entry, 34, IO_APIC_FIXED, DEST_PHYSICAL, IDLE, POLARITY_HIGH, IRR_RESET, EDGE_TRIGGER, MASKED, 0);
 
     // 计算HPET0间隔多少个时钟周期触发一次中断
-    uint64_t clks_to_intr = 0.001 * HPET0_INTERVAL * HPET_freq;
+    uint64_t clks_to_intr = 0.000001 * HPET0_INTERVAL * HPET_freq;
     // kdebug("clks_to_intr=%#ld", clks_to_intr);
     if (clks_to_intr <= 0 || clks_to_intr > (HPET_freq * 8))
     {
@@ -177,7 +177,7 @@ void HPET_enable()
     io_mfence();
     *(uint64_t *)(HPET_REG_BASE + TIM0_CONF) = 0x004c; // 设置定时器0为周期定时，边沿触发，默认投递到IO APIC的2号引脚(看conf寄存器的高32bit，哪一位被置1，则可以投递到哪一个I/O apic引脚)
     io_mfence();
-    *(uint64_t *)(HPET_REG_BASE + TIM0_COMP) = clks_to_intr; // 5ms触发一次中断
+    *(uint64_t *)(HPET_REG_BASE + TIM0_COMP) = clks_to_intr;
 
     io_mfence();
 
diff --git a/kernel/driver/timers/HPET/HPET.h b/kernel/driver/timers/HPET/HPET.h
index d94fc413..fe05afe4 100644
--- a/kernel/driver/timers/HPET/HPET.h
+++ b/kernel/driver/timers/HPET/HPET.h
@@ -6,7 +6,7 @@
 
 #define E_HPET_INIT_FAILED 1
 
-#define HPET0_INTERVAL 5    // HPET0定时器的中断间隔为5ms
+#define HPET0_INTERVAL 500    // HPET0定时器的中断间隔为500us
 int HPET_init();
 
 /**
diff --git a/kernel/time/timer.h b/kernel/time/timer.h
index 5dbc3271..8eb1dfc7 100644
--- a/kernel/time/timer.h
+++ b/kernel/time/timer.h
@@ -7,7 +7,9 @@
 uint64_t volatile timer_jiffies = 0; // 系统时钟计数
 
 // 计算接下来n毫秒对应的系统时间片
-#define cal_next_n_ms_jiffies(expire_ms) (timer_jiffies + expire_ms / 5 + ((expire_ms % HPET0_INTERVAL) ? 1 : 0))
+#define cal_next_n_ms_jiffies(expire_ms) (timer_jiffies + 1000*expire_ms / HPET0_INTERVAL + ((1000*expire_ms % HPET0_INTERVAL) ? 1 : 0))
+// 计算接下来n微秒对应的系统时间片
+#define cal_next_n_us_jiffies(expire_us) (timer_jiffies + expire_us / HPET0_INTERVAL + ((expire_us % HPET0_INTERVAL) ? 1 : 0))
 
 void timer_init();