graphic: 0.657
kernel: 0.638
device: 0.604
arm: 0.578
semantic: 0.494
debug: 0.487
architecture: 0.480
boot: 0.475
user-level: 0.416
virtual: 0.396
performance: 0.297
mistranslation: 0.294
PID: 0.238
register: 0.173
network: 0.172
permissions: 0.167
socket: 0.154
vnc: 0.130
hypervisor: 0.124
ppc: 0.124
x86: 0.117
risc-v: 0.111
peripherals: 0.101
VMM: 0.082
files: 0.070
assembly: 0.058
TCG: 0.039
i386: 0.018
KVM: 0.014

unable to boot arm64 image

Hi

Now I facing boot linux-5.3 arm64 image failed, without any log, just hang here.

Host machine: ubuntu-18.04 with 4.15.0-70-generic kernel
Qemu version: qemu-system-aarch64-version 4.1.0
use command: qemu-system-aarch64 -kernel <IAMGE> -append "console=ttyAMA0" -m 2048M -smp 2 -M virt -cpu cortex-a57 -nographic

could anyone teach me how to debug this?

You don't say anything about the kernel image you're trying to boot, but "nothing happens" is the expected result of trying to run a kernel which is not correctly configured to run on QEMU. You can debug in the same way you would debug "my kernel didn't boot on real hardware": try the gdb debugstub, try looking at the kernel config and comparing against a working version, etc.

https://translatedcode.wordpress.com/2017/07/24/installing-debian-on-qemus-64-bit-arm-virt-board/ is an example of a working setup of an aarch64 guest, which is probably a good place to start.